Re: [CentOS] Looking for back versions of centos 3
Am 13.02.2011 14:25, schrieb Bruce Ferrell: so far all the mirrors I've checked have 3.9 in the directory for 3.x Can anyone tell me how to get back versions? I'm looking for 3.4 or 3.5 Thanks in advance Bruce Ferrell http://vault.centos.org/ Alexander ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] Journal Aborts in VMware ESX (Filesystem Corruption)
I have several CentOS5 hosts in a VMware ESX 3.5.0 226117 environment using iSCSI storage. Recently we've begun to experience journal aborts resulting in remounted-read-only filesystems as well as other filesystem issues - I can unmount a filesystem and force a check with fsck -f and occasionally find errors. I've found - https://bugzilla.redhat.com/show_bug.cgi?id=228108 http://kb.vmware.com/selfservice/microsites/search.do?language=en_UScmd=displayKCexternalId=51306 - which seem related but I believe I am running a kernel that contains these fixes. My kernel is 2.6.18-194.32.1.el5 on one of the most effected hosts. Does anyone else have experience with similar issues or know of the status of this Bug/KB? I can install, boot, run, and then at some seemingly random moment - init_special_inode: bogus i_mode (50632) init_special_inode: bogus i_mode (137147) init_special_inode: bogus i_mode (172036) init_special_inode: bogus i_mode (175720) init_special_inode: bogus i_mode (72350) init_special_inode: bogus i_mode (174751) EXT3-fs error (device sdb2): ext3_lookup: unlinked inode 19698169 in dir #19696695 Aborting journal on device sdb2. init_special_inode: bogus i_mode (165661) EXT3-fs error (device sdb2): ext3_lookup: unlinked inode 19698131 in dir #19696695 init_special_inode: bogus i_mode (76763) init_special_inode: bogus i_mode (3116) init_special_inode: bogus i_mode (75363) init_special_inode: bogus i_mode (77034) init_special_inode: bogus i_mode (132237) EXT3-fs error (device sdb2): ext3_lookup: unlinked inode 19698139 in dir #19696695 init_special_inode: bogus i_mode (53031) init_special_inode: bogus i_mode (33361) init_special_inode: bogus i_mode (77546) init_special_inode: bogus i_mode (6516) EXT3-fs error (device sdb2): ext3_lookup: unlinked inode 19698143 in dir #19696695 init_special_inode: bogus i_mode (6442) init_special_inode: bogus i_mode (72554) EXT3-fs error (device sdb2): ext3_lookup: unlinked inode 19698142 in dir #19696695 EXT3-fs error (device sdb2): ext3_lookup: unlinked inode 19698164 in dir #19696695 init_special_inode: bogus i_mode (73171) init_special_inode: bogus i_mode (154432) init_special_inode: bogus i_mode (34302) init_special_inode: bogus i_mode (131733) init_special_inode: bogus i_mode (30773) ext3_abort called. EXT3-fs error (device sdb2): ext3_journal_start_sb: Detected aborted journal Remounting filesystem read-only ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] CentOS 64 bit php 5.2 huge problem
On Sat, 12 Feb 2011, Lamar Owen wrote: To: CentOS mailing list centos@centos.org From: Lamar Owen lo...@pari.edu Subject: Re: [CentOS] CentOS 64 bit php 5.2 huge problem On Saturday, February 12, 2011 07:03:59 pm Peter Ivanov wrote: My mysql.so is about 50K .. is that nornal No; the ones here are three times that size: [root@localhost ~]# ls -l /usr/lib64/mysql/libmysqlclient*.so.15.0.0 -rwxr-xr-x 1 root root 1517784 Nov 3 19:54 /usr/lib64/mysql/libmysqlclient_r.so.15.0.0 -rwxr-xr-x 1 root root 1510224 Nov 3 19:54 /usr/lib64/mysql/libmysqlclient.so.15.0.0 That doesn't sound too good. Is it possible that an attacker has uploaded replacement libraries with an evil payload - possibly to harvest your database contents? Maybe running Wireshark on the corrupted system will give you some clues as to whether data is being sent to a remote IP location, whenever a mysql query is executing? There could be *anything* in that payload to retrieve *all* the data from your database. Kind Regards, Keith - Websites: http://www.karsites.net http://www.php-debuggers.net http://www.raised-from-the-dead.org.uk All email addresses are challenge-response protected with TMDA [http://tmda.net] - ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] CentOS 64 bit php 5.2 huge problem
On Sun, 13 Feb 2011, Peter Ivanov wrote: To: CentOS mailing list centos@centos.org From: Peter Ivanov boksi...@gmail.com Subject: Re: [CentOS] CentOS 64 bit php 5.2 huge problem Thnaks Again, i guess i wont update the server until i find more info... i am happy it works now Personally I'd try and clone that corrupted system, and put it onto a spare machine for some forensic anaylysis. Maybe do a fresh installation on the running system, and use that for now? Just depends how much trouble it'g going to give you. Maybe this is where VM's come into their own? I'm not to hot on VM's but AFAICT can you do a fresh VM installation from a 'live' system, and then switch to that once it's setup. Is that correct? Kind Regards, Keith Roberts - Websites: http://www.karsites.net http://www.php-debuggers.net http://www.raised-from-the-dead.org.uk All email addresses are challenge-response protected with TMDA [http://tmda.net] - ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Journal Aborts in VMware ESX (Filesystem Corruption)
On Sun, Feb 13, 2011 at 9:09 AM, Adam Tauno Williams awill...@whitemice.org wrote: I have several CentOS5 hosts in a VMware ESX 3.5.0 226117 environment using iSCSI storage. Recently we've begun to experience journal aborts resulting in remounted-read-only filesystems as well as other filesystem issues - I can unmount a filesystem and force a check with fsck -f and occasionally find errors. I've found - https://bugzilla.redhat.com/show_bug.cgi?id=228108 http://kb.vmware.com/selfservice/microsites/search.do?language=en_UScmd=displayKCexternalId=51306 - which seem related but I believe I am running a kernel that contains these fixes. I ran into a similar problem, but it was not specifically iSCSI. We ended up setting a sysctl.conf file. Give me a few and I will find the setting.. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Journal Aborts in VMware ESX (Filesystem Corruption)
On Sun, Feb 13, 2011 at 9:09 AM, Adam Tauno Williams awill...@whitemice.org wrote: I have several CentOS5 hosts in a VMware ESX 3.5.0 226117 environment using iSCSI storage. Recently we've begun to experience journal aborts resulting in remounted-read-only filesystems as well as other filesystem issues - I can unmount a filesystem and force a check with fsck -f and occasionally find errors. http://communities.vmware.com/message/245983 The setting we used to resolve was vm.min_free_kbytes = 8192 Previous to this we were seeing the error pop up every week or so. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Looking for back versions of centos 3
On Sun, Feb 13, 2011 at 8:25 AM, Bruce Ferrell bferr...@baywinds.org wrote: so far all the mirrors I've checked have 3.9 in the directory for 3.x Can anyone tell me how to get back versions? I'm looking for 3.4 or 3.5 Thanks in advance Bruce Ferrell Bruce, *why*? Given that RHEL 3 was published in 1003, the codebase is over 7 years old, and even the commercial RHEL 3 is now on life support for extended support contracts. Are you looking for something specific? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] server specifications
Did somebody can give me some advises on hardware for building a Centos linux server? --- Michel Donais___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Michel Donais said the following on 13/02/11 16:26: Did somebody can give me some advises on hardware for building a Centos linux server? What will you put on that server? Ciao, luigi - -- / +--[Luigi Rosa]-- \ I used to wish the universe were fair. Then one day it hit me: What if the universe were fair? Then all the awful things that happen to us in life, would happen because we deserved them. So now I take great pleasure in the general hostility and unfairness of things. --Marcus Cole, A Late Delivery from Avalon, Babylon 5 -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk1X+q8ACgkQ3kWu7Tfl6ZQbUwCeMXL+bSJdxvylOfqZiVhQg9GF W5AAoL8+IZbBMd471QGFWDE1MHQHrXzT =Mluu -END PGP SIGNATURE- ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On 02/13/2011 10:26 AM, Michel Donais wrote: Did somebody can give me some advises on hardware for building a Centos linux server? Look for vendors that specifically list Red Hat Enterprise Linux 5 as a supported operating system. Most major vendors should offer servers with this support. If you are asking specs though, then you need to provide a lot more details on what the server will do. -- Digimer E-Mail: digi...@alteeve.com AN!Whitepapers: http://alteeve.com Node Assassin: http://nodeassassin.org ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
what about looking in the archives? You are really not the first person asking this. Kai ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] CentOS 64 bit php 5.2 huge problem
On Sun, 13 Feb 2011, Keith Roberts wrote: To: CentOS mailing list centos@centos.org From: Keith Roberts ke...@karsites.net Subject: Re: [CentOS] CentOS 64 bit php 5.2 huge problem On Sat, 12 Feb 2011, Lamar Owen wrote: To: CentOS mailing list centos@centos.org From: Lamar Owen lo...@pari.edu Subject: Re: [CentOS] CentOS 64 bit php 5.2 huge problem On Saturday, February 12, 2011 07:03:59 pm Peter Ivanov wrote: My mysql.so is about 50K .. is that nornal No; the ones here are three times that size: [root@localhost ~]# ls -l /usr/lib64/mysql/libmysqlclient*.so.15.0.0 -rwxr-xr-x 1 root root 1517784 Nov 3 19:54 /usr/lib64/mysql/libmysqlclient_r.so.15.0.0 -rwxr-xr-x 1 root root 1510224 Nov 3 19:54 /usr/lib64/mysql/libmysqlclient.so.15.0.0 That doesn't sound too good. Is it possible that an attacker has uploaded replacement libraries with an evil payload - possibly to harvest your database contents? Sorry - I thought it was Peter's libraries that are three time the normal size. Hence my reply. Kind Regards, Keith Maybe running Wireshark on the corrupted system will give you some clues as to whether data is being sent to a remote IP location, whenever a mysql query is executing? There could be *anything* in that payload to retrieve *all* the data from your database. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] CentOS 64 bit php 5.2 huge problem
On 13.2.2011 01:50, Lamar Owen wrote: On Feb 12, 2011, at 7:28 PM, Peter Ivanov wrote: PHP Startup: Unable to load dynamic library '/usr/lib64/php/modules/mysql.so' - libmysqlclient.so.15: cannot open shared object file: No such file or directory in Unknown on line 0 Run ldd /usr/lib64/php/modules/mysql.so and list the output. It should look something like: [root@localhost ~]# ldd /usr/lib64/php/modules/mysql.so Somewhat offtopic for sure, but maybe this should not be run as root https://bugzilla.redhat.com/show_bug.cgi?id=531160 -- Best Regards, Markus Falb signature.asc Description: OpenPGP digital signature ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] how do export a block device via eSATA?
Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA? I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC). Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work? The question is, how do I tell Linux to export a file system, or block device via the eSATA port? If any one has attempted this before, then please share some knowledge or pointers on the subject. I couldn't find anything using google, but I may not necessarily have searched for the correct terms? -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On 02/13/11 10:53 AM, Rudi Ahlers wrote: Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA? I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC). Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work? I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc) ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
At Sun, 13 Feb 2011 11:00:39 -0800 CentOS mailing list centos@centos.org wrote: On 02/13/11 10:53 AM, Rudi Ahlers wrote: Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA? I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC). Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work? I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc) More likely, it is running some custom software the connects to the exposed port (which is probably not a typical PC SATA port -- it would be wired like a Hard Drive's SATA connector (opposite gender, opposite signal directions, etc.). The custom software presents itself on this port like it was a hard drive and implements some sort of logical hard drive based on the actual internal hard drive -- not really much different from a USB connected mp3 player or camera -- the USB connected mp3 players / camera are just using a different physical interface (USB), but the logic is the same. Again, the USB port on these devices is 'wired' the opposite from the USB port on a normal PC and the logic behind it is also opposite (you cannot really connect a USB port of one PC to the USB port of another -- there is no such thing as a USB 'cross over' (Ethernet) or null-modem (RS232) cable in the USB (or firewire) world). The processor in the little box is implementing much that same sort of processing that goes on inside the micro processor on the controller board of a hard drive -- modern hard drive controller boards are really a full fledged little computer running a very special program that implements the drive end of the mass storage interface (SCSI, SATA, PATA, etc.). The media tank is just taking this to a different level. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Robert Heller -- 978-544-6933 / hel...@deepsoft.com Deepwoods Software-- http://www.deepsoft.com/ () ascii ribbon campaign -- against html e-mail /\ www.asciiribbon.org -- against proprietary attachments ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On Sun, Feb 13, 2011 at 9:44 PM, Robert Heller hel...@deepsoft.com wrote: At Sun, 13 Feb 2011 11:00:39 -0800 CentOS mailing list centos@centos.org wrote: On 02/13/11 10:53 AM, Rudi Ahlers wrote: Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA? I have a cheat ($15 probably?) media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC). Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work? I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc) More likely, it is running some custom software the connects to the exposed port (which is probably not a typical PC SATA port -- it would be wired like a Hard Drive's SATA connector (opposite gender, opposite signal directions, etc.). The custom software presents itself on this port like it was a hard drive and implements some sort of logical hard drive based on the actual internal hard drive -- not really much different from a USB connected mp3 player or camera -- the USB connected mp3 players / camera are just using a different physical interface (USB), but the logic is the same. Again, the USB port on these devices is 'wired' the opposite from the USB port on a normal PC and the logic behind it is also opposite (you cannot really connect a USB port of one PC to the USB port of another -- there is no such thing as a USB 'cross over' (Ethernet) or null-modem (RS232) cable in the USB (or firewire) world). The processor in the little box is implementing much that same sort of processing that goes on inside the micro processor on the controller board of a hard drive -- modern hard drive controller boards are really a full fledged little computer running a very special program that implements the drive end of the mass storage interface (SCSI, SATA, PATA, etc.). The media tank is just taking this to a different level. Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation. I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN. P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable - they work quite well. They're not as fast a gigabit but works very well for older PC's without LAN. -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] Software RAID vs 'fake/ on-board RAID'
Setting: We are setting up a low usage server for an alfresco km/collaboration system It is a low-end server with a pair of 1.5 TB disks we will be mirroring The server comes with Intel's on-board 'fake raid/ low-end RAID' capability and for price reasons we have not selected a mainstream RAID card Prior thoughts: Searches on the net indicate no performance advantage, and possible performance disadvantages to the on-board RAID I expect Intel the Centos product to be rough equivalents in quality I am leaning to software RAID for a simple reason of minimizing my administration operational burden. If I need to perform repairs, obtain alerts it is the same administration toolset rather than a BIOS-based tool that seems to be accessible only through boot/ reboot. Question: Over a reasonable lifecycle are we better served going with the on-board or Centos' software RAID? Any issue with booting from the RAID (obviously RAID 1)? Thanks in advance for your thoughts. Dave ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Software RAID vs 'fake/ on-board RAID'
On Sun, Feb 13, 2011 at 11:07 PM, David Hornford d...@qillaq.com wrote: Setting: We are setting up a low usage server for an alfresco km/collaboration system It is a low-end server with a pair of 1.5 TB disks we will be mirroring The server comes with Intel's on-board 'fake raid/ low-end RAID' capability and for price reasons we have not selected a mainstream RAID card Prior thoughts: Searches on the net indicate no performance advantage, and possible performance disadvantages to the on-board RAID I expect Intel the Centos product to be rough equivalents in quality I am leaning to software RAID for a simple reason of minimizing my administration operational burden. If I need to perform repairs, obtain alerts it is the same administration toolset rather than a BIOS-based tool that seems to be accessible only through boot/ reboot. Question: Over a reasonable lifecycle are we better served going with the on-board or Centos' software RAID? Any issue with booting from the RAID (obviously RAID 1)? Thanks in advance for your thoughts. Dave ___ You'll get the same benefits by using Linux's software RAID + it's easier to setup and you won't be vendor tied, i.e. if the motherboard packs up and you can't get exactly the same one, or another one with the same RAID chipset. You simply put the drives into another PC and you're up and running again. -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] Security: gnome-screensaver VS. switch user
People usually suspend their laptop, so that they can continue their work when they open the laptop. OK! Two choices [GNOME]: 1 - Menu -gt; Shut Down -gt; Suspend in this case, the gnome-screensaver locks the PC. but the gnome-screensaver is just a normal process, and it could be killed e.g.: http://securitytube.net/USB-Autorun-attacks-against-Linux-at-Shmoocon-2011-video.aspx or using any method [video was just an example!!]. 2 - Menu -gt; Log out -gt; Switch user -gt; Suspend in this case, the GDM [???] protects the user [i mean it locks the PC from other users] Which one is more secure/safer? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Journal Aborts in VMware ESX (Filesystem Corruption)
Hi Also seeing this issue with CentOS 5.4 and 5.5 with NFS shared storage, according the the VMware knowledge base article this should have been resolved in v5.1 update??. Does changing the vm.min_free_kbytes value apply CentOS v.5.4 and 5.5 as well to resolve the issue? On 13 Feb 2011, at 14:40, Kwan Lowe kwan.l...@gmail.com wrote: On Sun, Feb 13, 2011 at 9:09 AM, Adam Tauno Williams awill...@whitemice.org wrote: I have several CentOS5 hosts in a VMware ESX 3.5.0 226117 environment using iSCSI storage. Recently we've begun to experience journal aborts resulting in remounted-read-only filesystems as well as other filesystem issues - I can unmount a filesystem and force a check with fsck -f and occasionally find errors. http://communities.vmware.com/message/245983 The setting we used to resolve was vm.min_free_kbytes = 8192 Previous to this we were seeing the error pop up every week or so. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
At Sun, 13 Feb 2011 21:58:11 +0200 CentOS mailing list centos@centos.org wrote: On Sun, Feb 13, 2011 at 9:44 PM, Robert Heller hel...@deepsoft.com wrote: At Sun, 13 Feb 2011 11:00:39 -0800 CentOS mailing list centos@centos.org wrote: On 02/13/11 10:53 AM, Rudi Ahlers wrote: Does any one know how to, if at all possible currently, to export a block device via eSATA? i.e. how do I do something like iSCSI, but over eSATA? I have a cheat ($15 probably?) Â media player at home (Egreat EG-M31B Network Media Tank - awesome little machine) that runs some flavor of Debian and can be connected to any PC via eSATA as an external HDD's. i.e. it exports the built-in HDD as a block device to the host (My laptop or PC). Now, the question is, how can I do this on Linux? Would I need a different eSATA card than the on-board eSATA port on most motherboards? Or would the on-board one work? I suspect your media tank is doing something electrical, like idling its processor, and re-routing the sata port directly to the internal storage device, when its in this mode. Â I'm unaware of any SATA target drivers (as opposed to the normal initiator drivers in libata etc) More likely, it is running some custom software the connects to the exposed port (which is probably not a typical PC SATA port -- it would be wired like a Hard Drive's SATA connector (opposite gender, opposite signal directions, etc.). Â The custom software presents itself on this port like it was a hard drive and implements some sort of logical hard drive based on the actual internal hard drive -- not really much different from a USB connected mp3 player or camera -- the USB connected mp3 players / camera are just using a different physical interface (USB), but the logic is the same. Again, the USB port on these devices is 'wired' the opposite from the USB port on a normal PC and the logic behind it is also opposite (you cannot really connect a USB port of one PC to the USB port of another -- there is no such thing as a USB 'cross over' (Ethernet) or null-modem (RS232) cable in the USB (or firewire) world). The processor in the little box is implementing much that same sort of processing that goes on inside the micro processor on the controller board of a hard drive -- modern hard drive controller boards are really a full fledged little computer running a very special program that implements the drive end of the mass storage interface (SCSI, SATA, PATA, etc.). Â The media tank is just taking this to a different level. Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation. You probably can't do it with 'a normal / server motherboard'. The SATA / eSATA ports on such a board are 'host' ports. You would need a 'disk' port, which is *electrically* different -- it is no different than with USB or Firewire devices. There is the 'host' side and there is the 'device' side. They are different. I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN. P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable - they work quite well. They're not as fast a gigabit but works very well for older PC's without LAN. -- Robert Heller -- 978-544-6933 / hel...@deepsoft.com Deepwoods Software-- http://www.deepsoft.com/ () ascii ribbon campaign -- against html e-mail /\ www.asciiribbon.org -- against proprietary attachments ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Software RAID vs 'fake/ on-board RAID'
At Sun, 13 Feb 2011 13:07:09 -0800 CentOS mailing list centos@centos.org wrote: Setting: We are setting up a low usage server for an alfresco km/collaboration system It is a low-end server with a pair of 1.5 TB disks we will be mirroring The server comes with Intel's on-board 'fake raid/ low-end RAID' capability and for price reasons we have not selected a mainstream RAID card Prior thoughts: Searches on the net indicate no performance advantage, and possible performance disadvantages to the on-board RAID I expect Intel the Centos product to be rough equivalents in quality I am leaning to software RAID for a simple reason of minimizing my administration operational burden. If I need to perform repairs, obtain alerts it is the same administration toolset rather than a BIOS-based tool that seems to be accessible only through boot/ reboot. Question: Over a reasonable lifecycle are we better served going with the on-board or Centos' software RAID? Any issue with booting from the RAID (obviously RAID 1)? You are always going to be better off using Linux (CentOS) software RAID. There are no issues with booting off a RAID 1. You'll create two partitions on the disks: a small one for /boot and the rest to be a LVM volume group (carved into swap, /, and your data and/or /home). You'll make two RAID sets, one for /boot and the other for the LVM volume group. The only trickyness is to be sure to install grub on both disks -- this lets you boot off /dev/sdb if/when /dev/sda dies. Thanks in advance for your thoughts. Dave MIME-Version: 1.0 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Robert Heller -- 978-544-6933 / hel...@deepsoft.com Deepwoods Software-- http://www.deepsoft.com/ () ascii ribbon campaign -- against html e-mail /\ www.asciiribbon.org -- against proprietary attachments ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On 02/13/11 12:28 PM, Robert Heller wrote: it is no different than with USB or Firewire devices. There is the 'host' side and there is the 'device' side. They are different. actually, firewire is a peer to peer bus, like ethernet. there's no 'host' or 'device', there is just firewire. /pendantic ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On 2/13/11 1:58 PM, Rudi Ahlers wrote: Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation. If you are going to pass eSATA straight through, why would you want the other motherboard involved at all instead of just using an external eSata enclosure? I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN. It might make sense to RAID a bunch of disks locally, and export the combined device as iscsi. P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable - they work quite well. They're not as fast a gigabit but works very well for older PC's without LAN. I thought those were really implemented as back-to-back ethernet converters. -- Les Mikesell lesmikes...@gmail.com ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On Sun, Feb 13, 2011 at 11:10 PM, Les Mikesell lesmikes...@gmail.com wrote: On 2/13/11 1:58 PM, Rudi Ahlers wrote: Sure, I understand what you're saying, but the question is: If they can do it with a cheap device like this, then surely one should be able todo it with a normal / server motherboard? Obviously they won't tell us their secrets, so I need to dig around to see how todo it myself. This particular device has a eSATA slave + eSATA Master mode. i.e. I can connect another device to this one and they both work together, and then when I connect the first one to my PC, I have 2 HDD's - i.e. a cheap JBOD implementation. If you are going to pass eSATA straight through, why would you want the other motherboard involved at all instead of just using an external eSata enclosure? I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :) I'm trying to see if I can setup a Linux JBOD on a server chassis with say 16 HDD's or something, and then connect it to another server via eSATA - i.e. building a cheap scalable SAN. It might make sense to RAID a bunch of disks locally, and export the combined device as iscsi. The 1GBE LAN is a bit slow. SATA can push 6GBe, which is 6 times faster than 1GBe. And, 6 ports on a LAN switch is a waste. Our 10GBe switches are saturated (all ports filled) and very expensive. So I'm looking at cheaper options, and thought eSATA could do the trick quite well. P.S. You actually do get USB cross-over cables: http://en.kioskea.net/faq/342-connecting-two-computers-with-a-usb-cable - they work quite well. They're not as fast a gigabit but works very well for older PC's without LAN. I thought those were really implemented as back-to-back ethernet converters. Yes, probably. But they work over USB so it's very handy. -- Les Mikesell lesmikes...@gmail.com ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Security: gnome-screensaver VS. switch user
On Sun, Feb 13, 2011 at 12:26 PM, erikmccaskey64 erikmccaske...@zoho.com wrote: People usually suspend their laptop, so that they can continue their work when they open the laptop. OK! Two choices [GNOME]: 1 - Menu - Shut Down - Suspend in this case, the gnome-screensaver locks the PC. but the gnome-screensaver is just a normal process, and it could be killed e.g.: http://securitytube.net/USB-Autorun-attacks-against-Linux-at-Shmoocon-2011-video.aspx or using any method [video was just an example!!]. 2 - Menu - Log out - Switch user - Suspend in this case, the GDM [???] protects the user [i mean it locks the PC from other users] Which one is more secure/safer? You should consider asking this in the gnome users's group rather than two (or more?) OS groups that happen to use gnome. There is a third option, hibernation, which you did not mention, but essentially they are all more or less equally secure - they all require login password authentication to resume operation once the computer is brought back. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On 02/13/11 1:21 PM, Rudi Ahlers wrote: I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :) thats a stunningly bad way to go about it. A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing. or B) if you want a SAN, use iSCSI or FCoE or something. or C) if you want a NAS, use NFS. this is the best solution for many applications. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pie...@hogranch.com wrote: On 02/13/11 1:21 PM, Rudi Ahlers wrote: I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :) thats a stunningly bad way to go about it. A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing. mmm, I didn't think of this :) or B) if you want a SAN, use iSCSI or FCoE or something. As I said, I'm trying todo something cheaper. These are super expensive in our country. or C) if you want a NAS, use NFS. this is the best solution for many applications. We already use iSCSI, which is a bit quicker than NFS I'm merely exploring this new technology, seeing as so many vendor incorporate it into cheap NAS devices (which are normally limited to 2 - 5 drives) to see if it could actually be used on a bigger scale. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Security: gnome-screensaver VS. switch user
On Sun, 2011-02-13 at 13:22 -0800, Mark wrote: There is a third option, hibernation, which you did not mention, but essentially they are all more or less equally secure - they all require login password authentication to resume operation once the computer is brought back. This is definitely NOT the case with my netbook running C 5.5. I shut the lid at a friend's home several days ago. I opened the lid this evening and was presented with exactly the same spot on the web page I previously looked-at. The settings was Battery and Suspend. No LURS, no password, no nothing AND I logged-on automatically to my WPA2 home network. I will try the hibernate setting later. -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
Before any possible answer can be given, the first question must be: What do you plan to do with it? You'r right, but I have to begin somewhere. This hardware is intended to be a terminal server for at least 40 users driven with LTSP.for BBx Pro-5 and Bbj applications Need fast and huge storage, 2 lan fast connexions. No intensive mail or web browsing, 1 or 2 outside (xtranet ) users; back-up will be on an SLR-100 tape drive The load for 20 users and for the last 6 years with RH9 is actually supported by a MOTHER BOARD : MSI KT-3 ULTRA DDR 333(3) CE (ATX form) CPU : AMD-2100 XP memory : 2 DDRam 333 (512MEG) for a total of 1024meg 1 scsi controller adaptec 29160 SCSI 3 hard disc SEAGATE CHETAH ULTRA SCSI-ULTRA-320 LVD (68 pin) It have been enough for that tme but users number is raising and by the way an upgrade of the computing capacity will be usefull. I checked recently for an ASUS S775 P5Q-VM G45 PCIE MOTHERBOARD with an INTEL CORE 2 QUAD Q9550 2.83G/1333/12M/S775 with SATA hard disc no Raid I doesn't seem to be a server board and I'm not shure of that choice. --- Michel Donais ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
2011/2/14 Michel Donais don...@telupton.com: Before any possible answer can be given, the first question must be: What do you plan to do with it? You'r right, but I have to begin somewhere. This hardware is intended to be a terminal server for at least 40 users driven with LTSP.for BBx Pro-5 and Bbj applications Need fast and huge storage, 2 lan fast connexions. No intensive mail or web browsing, 1 or 2 outside (xtranet ) users; back-up will be on an SLR-100 tape drive The load for 20 users and for the last 6 years with RH9 is actually supported by a MOTHER BOARD : MSI KT-3 ULTRA DDR 333(3) CE (ATX form) CPU : AMD-2100 XP memory : 2 DDRam 333 (512MEG) for a total of 1024meg 1 scsi controller adaptec 29160 SCSI 3 hard disc SEAGATE CHETAH ULTRA SCSI-ULTRA-320 LVD (68 pin) It have been enough for that tme but users number is raising and by the way an upgrade of the computing capacity will be usefull. I checked recently for an ASUS S775 P5Q-VM G45 PCIE MOTHERBOARD with an INTEL CORE 2 QUAD Q9550 2.83G/1333/12M/S775 with SATA hard disc no Raid I doesn't seem to be a server board and I'm not shure of that choice. Maybe you just want to pick real server hardware? Pick one of Dell RXX series. -- Eero ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On 02/13/11 2:42 PM, Michel Donais wrote: I checked recently for an ASUS S775 P5Q-VM G45 PCIE MOTHERBOARD with an INTEL CORE 2 QUAD Q9550 2.83G/1333/12M/S775 with SATA hard disc no Raid I doesn't seem to be a server board and I'm not shure of that choice. thats desktop hardware. no ECC support. anything running a business application for 50 users is probably mission important or mission critical, and undetected creeping bit errors due to lack of ECC would be, in my book, unacceptable. I'd probably use a HP or Dell 1U or 2U server, with redundant power, ECC memory, and at least mirrored system drives. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Journal Aborts in VMware ESX (Filesystem Corruption)
On Sun, 2011-02-13 at 09:40 -0500, Kwan Lowe wrote: On Sun, Feb 13, 2011 at 9:09 AM, Adam Tauno Williams awill...@whitemice.org wrote: I have several CentOS5 hosts in a VMware ESX 3.5.0 226117 environment using iSCSI storage. Recently we've begun to experience journal aborts resulting in remounted-read-only filesystems as well as other filesystem issues - I can unmount a filesystem and force a check with fsck -f and occasionally find errors. http://communities.vmware.com/message/245983 The setting we used to resolve was vm.min_free_kbytes = 8192 Previous to this we were seeing the error pop up every week or so. You made this change to the *virtual machine* [not the host OS]? This thread indicates this was with VMware Workstation and not ESX (correct)? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Journal Aborts in VMware ESX (Filesystem Corruption)
On Sun, 2011-02-13 at 20:28 +, Keith Beeby wrote: Also seeing this issue with CentOS 5.4 and 5.5 with NFS shared storage, according the the VMware knowledge base article this should have been resolved in v5.1 update??. Does changing the vm.min_free_kbytes valu apply CentOS v.5.4 and 5.5 as well to resolve the issue? I guess we'll see [this issue has become extremely frustrating]. I suppose it is 'good' to see that someone else sees the issue as well. One issue with virtualization is that debugging these types of issues is an order-of-magnitude more difficult [virtualized OS, virtualized storage, virtualization platform, or some interaction of all the above... ugh]. On 13 Feb 2011, at 14:40, Kwan Lowe kwan.l...@gmail.com wrote: On Sun, Feb 13, 2011 at 9:09 AM, Adam Tauno Williams awill...@whitemice.org wrote: I have several CentOS5 hosts in a VMware ESX 3.5.0 226117 environment using iSCSI storage. Recently we've begun to experience journal aborts resulting in remounted-read-only filesystems as well as other filesystem issues - I can unmount a filesystem and force a check with fsck -f and occasionally find errors. http://communities.vmware.com/message/245983 The setting we used to resolve was vm.min_free_kbytes = 8192 Previous to this we were seeing the error pop up every week or so. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
undetected creeping bit errors due to lack of ECC would be, in my book, unacceptable. Where can one find info or studies on this sort of thing? I use non-ecc ram in several servers, and of course most ppl use it in their desktops. Wouldn't bit errors result in crashes or data corruption? Or what would the results be? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On 2/13/11 7:55 PM, compdoc wrote: undetected creeping bit errors due to lack of ECC would be, in my book, unacceptable. Where can one find info or studies on this sort of thing? I use non-ecc ram in several servers, and of course most ppl use it in their desktops. Wouldn't bit errors result in crashes or data corruption? Or what would the results be? It's very unpredictable. Since linux tends to use all available ram for disk buffers, the first thing is likely to be corruption in disk files. By the time you see crashes or anything visible, you may have a lot of invalid data. -- Les Mikesell lesmikes...@gmail.com ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On Sun, Feb 13, 2011 at 8:55 PM, compdoc comp...@hotrodpc.com wrote: undetected creeping bit errors due to lack of ECC would be, in my book, unacceptable. Where can one find info or studies on this sort of thing? I use non-ecc ram in several servers, and of course most ppl use it in their desktops. Wouldn't bit errors result in crashes or data corruption? Or what would the results be? ECC allows for single bit errors to be corrected and multiple bit errors to be noticed. All our servers run ECC memory. I've had memory go bad where the logs were showing correctable ECC errors. Since they were correctable no data was corrupt and I was able to replace the bad memory. Had I been using regular memory who knows what data could have been potentially corrupt. Just like you use RAID to provide higher reliability for drives you should use ECC memory. The cost different is negligible. Ryan ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
ECC allows for single bit errors to be corrected and multiple bit errors to be noticed. I know what it is and I've used it in the past, but I just don't see many errors going on in desktop computers and servers that use non-ecc ram. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On Sun, 2011-02-13 at 19:21 -0700, compdoc wrote: ECC allows for single bit errors to be corrected and multiple bit errors to be noticed. I know what it is and I've used it in the past, but I just don't see many errors going on in desktop computers and servers that use non-ecc ram. I agree: ditto servers, VPSs, laptops, netbooks and desktops running C5.5. -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On Feb 13, 2011, at 4:59 PM, Rudi Ahlers r...@softdux.com wrote: On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pie...@hogranch.com wrote: On 02/13/11 1:21 PM, Rudi Ahlers wrote: I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :) thats a stunningly bad way to go about it. A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing. mmm, I didn't think of this :) Dell has the MD1120 which is a 24 bay 2.5 SAS/SATA enclosure. I think it goes for $3000 plus cost of disk drives. If you want to go cheaper I believe Supermicro makes a 16 drive chassis that is meant for a server, but can be made into an external enclosure, or an iSCSI/NFS/CIFS storage server. -Ross ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On Sun, Feb 13, 2011 at 7:01 PM, John R Pierce pie...@hogranch.com wrote: On 02/13/11 2:42 PM, Michel Donais wrote: I checked recently for an ASUS S775 P5Q-VM G45 PCIE MOTHERBOARD with an INTEL CORE 2 QUAD Q9550 2.83G/1333/12M/S775 with SATA hard disc no Raid I doesn't seem to be a server board and I'm not shure of that choice. thats desktop hardware. no ECC support. anything running a business application for 50 users is probably mission important or mission critical, and undetected creeping bit errors due to lack of ECC would be, in my book, unacceptable. I'd probably use a HP or Dell 1U or 2U server, with redundant power, ECC memory, and at least mirrored system drives. It's also possible to save the budget, buy *two* similarly powerful used systems with much lesser hardware specs, and have genuine failover instead of the shared vulnerability of one expensive server with high-availability components as you describe. I've done both, and encourage using less expensive hardware in pairs: that makes upgrading a lot cheaper and helps avoid the single points of failure of high end hardware. HP's older Proliant Server Packs and their ability to completely mishandle the Broadcom network drivers on RHEL and CentOS, in particular, come to mind. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Looking for back versions of centos 3
On Sun, Feb 13, 2011 at 9:23 PM, Ross Walker rswwal...@gmail.com wrote: On Feb 13, 2011, at 10:22 AM, Nico Kadel-Garcia nka...@gmail.com wrote: On Sun, Feb 13, 2011 at 8:25 AM, Bruce Ferrell bferr...@baywinds.org wrote: so far all the mirrors I've checked have 3.9 in the directory for 3.x Can anyone tell me how to get back versions? I'm looking for 3.4 or 3.5 Thanks in advance Bruce Ferrell Bruce, *why*? Given that RHEL 3 was published in 1003, the codebase is over 7 years old, and even the commercial RHEL 3 is now on life support for extended support contracts. Are you looking for something specific? Wow 1007 years old, that's some old code, was it chiseled in stone? -Ross Hey, silicon is silicon. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On 02/13/11 7:06 PM, Nico Kadel-Garcia wrote: It's also possible to save the budget, buy *two* similarly powerful used systems with much lesser hardware specs, and have genuine failover instead of the shared vulnerability of one expensive server with high-availability components as you describe. I've done both, and encourage using less expensive hardware in pairs: that makes upgrading a lot cheaper and helps avoid the single points of failure of high end hardware. HP's older Proliant Server Packs and their ability to completely mishandle the Broadcom network drivers on RHEL and CentOS, in particular, come to mind. you still want ECC memory in a server...and redundant power in a 1U is really no big deal. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
By doubling the hardware, you still do not overcome the potential corruption that could occur with non-ecc memory. If this is truly a mission critical application then it really does not serve much of a purpose to short change yourself with substandard hardware. -Original Message- From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On Behalf Of John R Pierce Sent: Sunday, February 13, 2011 7:17 PM To: centos@centos.org Subject: Re: [CentOS] server specifications On 02/13/11 7:06 PM, Nico Kadel-Garcia wrote: It's also possible to save the budget, buy *two* similarly powerful used systems with much lesser hardware specs, and have genuine failover instead of the shared vulnerability of one expensive server with high-availability components as you describe. I've done both, and encourage using less expensive hardware in pairs: that makes upgrading a lot cheaper and helps avoid the single points of failure of high end hardware. HP's older Proliant Server Packs and their ability to completely mishandle the Broadcom network drivers on RHEL and CentOS, in particular, come to mind. you still want ECC memory in a server...and redundant power in a 1U is really no big deal. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On Sun, Feb 13, 2011 at 10:23 PM, David Brian Chait dch...@invenda.com wrote: By doubling the hardware, you still do not overcome the potential corruption that could occur with non-ecc memory. If this is truly a mission critical application then it really does not serve much of a purpose to short change yourself with substandard hardware. First, please don't top post in this group. Second, you've got a historically valid point about ECC's advantages. But the accumulated costs of the higher end motherboard, memory, shortage of space for upgrades in the same unit, the downtime at the BIOS to reset the disabled by default ECC settings in the BIOS, and the system monitoring to detect and manage such errors add up *really fast* in a moderate sized shop. Worse, I've seen some serious false economies with memory. People with tight budgets getting third party memory to install themselves, then losing all their savings in downtime because they had trouble telling the difference between hard enough to seat the RAM and hard enough to crack the motherboard, cut your hand, and bleed all over important junctions. Pleae, name a single instance in the last 10 years where ECC demonstrably saved you work, especially if you made sure ti burn in the ssytem components on servers upon their first bootup... ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
Nico Kadel-Garcia wrote: On Sun, Feb 13, 2011 at 10:23 PM, David Brian Chait dch...@invenda.com wrote: By doubling the hardware, you still do not overcome the potential corruption that could occur with non-ecc memory. If this is truly a mission critical application then it really does not serve much of a purpose to short change yourself with substandard hardware. First, please don't top post in this group. Second, you've got a historically valid point about ECC's advantages. But the accumulated costs of the higher end motherboard, memory, shortage of space for upgrades in the same unit, the downtime at the BIOS to reset the disabled by default ECC settings in the BIOS, and the system monitoring to detect and manage such errors add up *really fast* in a moderate sized shop. Worse, I've seen some serious false economies with memory. People with tight budgets getting third party memory to install themselves, then losing all their savings in downtime because they had trouble telling the difference between hard enough to seat the RAM and hard enough to crack the motherboard, cut your hand, and bleed all over important junctions. Pleae, name a single instance in the last 10 years where ECC demonstrably saved you work, especially if you made sure ti burn in the ssytem components on servers upon their first bootup... Twice in the last two years my intel server mb with ECC RAM showed errors (after moving system physically) and thus I did a reseat (after cleaning) of the modules and all is now well. No data lost, complete confidence - definitely gets my vote for servers!! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos attachment: rkampen.vcf___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On Mon, Feb 14, 2011 at 12:16 AM, Rob Kampen rkam...@kampensonline.com wrote: Nico Kadel-Garcia wrote: Pleae, name a single instance in the last 10 years where ECC demonstrably saved you work, especially if you made sure ti burn in the ssytem components on servers upon their first bootup... Twice in the last two years my intel server mb with ECC RAM showed errors (after moving system physically) and thus I did a reseat (after cleaning) of the modules and all is now well. No data lost, complete confidence - definitely gets my vote for servers!! Same system? Did you burn it in (running it under serious load with memory and CPU testing tools for a day or two after initial installation)? And given that you opened it up, I also assume you cleaned out accumulated dust and cleaned the filters. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] server specifications
On 2/14/2011 12:29 AM, Nico Kadel-Garcia wrote: On Mon, Feb 14, 2011 at 12:16 AM, Rob Kampenrkam...@kampensonline.com wrote: Nico Kadel-Garcia wrote: Pleae, name a single instance in the last 10 years where ECC demonstrably saved you work, especially if you made sure ti burn in the ssytem components on servers upon their first bootup... Twice in the last two years my intel server mb with ECC RAM showed errors (after moving system physically) and thus I did a reseat (after cleaning) of the modules and all is now well. No data lost, complete confidence - definitely gets my vote for servers!! Same system? Did you burn it in (running it under serious load with memory and CPU testing tools for a day or two after initial installation)? And given that you opened it up, I also assume you cleaned out accumulated dust and cleaned the filters. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos A burn in only tests the ram at burn in. Later as parts wear(and electronic parts DO wear) bit errors can begin. There's two ways to hanlde this: 1. spend maybe 5% more for ecc memory so bit errors can be either fixed or alerte3d automatically 2. save 5% money wise but loose more time to burn in your system at regular intervals to make sure nothing is failing 3. Do nothing. Save the 5% and go with the...it's worked before... When number 3 bites you in the arse the costs of your penny-pinching laziness will be many orders of magnitude higher..due to file system corruption, backup corruption..etc etc etc. If the system is doing bit errors those bit errors WILL show up in your backups. If the machine has been in service for years...the costs are even more drastic. Spend 5% on ECC and number 3 won't bite you in the arse...unless you don't monitor your systems at all..then you are going to get hosed anyway. This is one time the 5% is worth the cost. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Looking for back versions of centos 3
On 02/13/2011 07:07 PM, Nico Kadel-Garcia wrote: On Sun, Feb 13, 2011 at 9:23 PM, Ross Walker rswwal...@gmail.com wrote: On Feb 13, 2011, at 10:22 AM, Nico Kadel-Garcia nka...@gmail.com wrote: On Sun, Feb 13, 2011 at 8:25 AM, Bruce Ferrell bferr...@baywinds.org wrote: so far all the mirrors I've checked have 3.9 in the directory for 3.x Can anyone tell me how to get back versions? I'm looking for 3.4 or 3.5 Thanks in advance Bruce Ferrell Bruce, *why*? Given that RHEL 3 was published in 1003, the codebase is over 7 years old, and even the commercial RHEL 3 is now on life support for extended support contracts. Are you looking for something specific? Wow 1007 years old, that's some old code, was it chiseled in stone? -Ross Hey, silicon is silicon. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos Yeah, I'm rebuilding a server with Oracle RAC and I wasn't sure exactly what version of RedHat was used to build it originally. Centos 5.5 results in the external iscsi volumes being improperly sized. It turns out Centos 3.5 works. Once, many years ago, someone told me he wouldn't tackle a job he was 100 percent sure of. This is one of those so I'm doing this very gingerly to avoide losing the DB on the raw disk ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] how do export a block device via eSATA?
On Mon, Feb 14, 2011 at 4:44 AM, Ross Walker rswwal...@gmail.com wrote: On Feb 13, 2011, at 4:59 PM, Rudi Ahlers r...@softdux.com wrote: On Sun, Feb 13, 2011 at 11:35 PM, John R Pierce pie...@hogranch.com wrote: On 02/13/11 1:21 PM, Rudi Ahlers wrote: I'm trying to build a dense eSATA enclosure with say 16 or 24 drives :) thats a stunningly bad way to go about it. A) if you want JBOD, use a SAS/SATA enclosure with a SAS host card, as SATA doesn't support multichannel multiplexing. mmm, I didn't think of this :) Dell has the MD1120 which is a 24 bay 2.5 SAS/SATA enclosure. I think it goes for $3000 plus cost of disk drives. If you want to go cheaper I believe Supermicro makes a 16 drive chassis that is meant for a server, but can be made into an external enclosure, or an iSCSI/NFS/CIFS storage server. -Ross Thanx Ross. We got those 16 drive SuperMicro chassis, which is what I want to use, and they're already running FreeNAS which offers iSCSI NFS. I just had this idea of exploring eSATA since most machines already have an eSATA port. So if I don't get this working, it's not a big deal. But, I think it could be a cheap alternative to SAS / FC interconnect. -- Kind Regards Rudi Ahlers SoftDux Website: http://www.SoftDux.com Technical Blog: http://Blog.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS-virt] using an lvm for kvm vm
On 02/13/2011 09:27 AM, Nataraj wrote: Is there a simple way to directly install a vm on an lvm (or proably seperate LVM's for root and swap)? For example something like: lvcreate -L 10G -n testvm_root vg_myvg lvcreate -L 1G -n testvm_swap Then somehow setup the VM to be able to directly install and boot the vm from these LV's. How do I do this? You can do this with virt-manager. Just specify the logical volume as storage instead of a file. You'd have to add the swap space after the installation though. The way I do this is to create just one logical volume for the VM with 11G and the in the guest specify one 10G volume for root and 1G for swap. That way you only have one logical volume per VM on the host. Could you then pause the virtual machine and safely take an LVM snapshot, continue the VM and then mount the snapshot on the host and do a backup? Probably not. If you pause the guest then the filesystem on it might be in an inconsistent state. You will be able to make a snapshot since that happens on the block level but you might have problems mounting it. Regards, Dennis ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] using an lvm for kvm vm
On 02/13/2011 12:18 PM, Kenni Lund wrote: 2011/2/13 Dennis Jacobfeuerborn denni...@conversis.de: On 02/13/2011 09:27 AM, Nataraj wrote: Is there a simple way to directly install a vm on an lvm (or proably seperate LVM's for root and swap)? For example something like: Use a volume group as a storage pool in virsh/virt-manager: http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization/chap-Virtualization-Storage_Pools-Storage_Pools.html#sect-Virtualization-Storage_Pools-Creating-LVM Best regards Kenni ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt Thank you. This is what I was looking for. Nataraj ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] using an lvm for kvm vm
On 02/13/2011 10:21 AM, Dennis Jacobfeuerborn wrote: Could you then pause the virtual machine and safely take an LVM snapshot, continue the VM and then mount the snapshot on the host and do a backup? Probably not. If you pause the guest then the filesystem on it might be in an inconsistent state. You will be able to make a snapshot since that happens on the block level but you might have problems mounting it. Regards, Dennis I've heard of somebody doing something to make this work. I think you could create another LV (from inside the VM - assuming a linux VM) on top of whatever raw partition was available to the VM. Then you could take the snapshot within the VM (which I believe guarantees that the filesystem is sync'ed when the snapshot is taken.) Then you use losetup and lvscan to make the lvm vg available on the host and I think you could access the snapshot without even pausing the vm. Nataraj ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] using an lvm for kvm vm
On 02/13/2011 02:30 PM, Nataraj wrote: On 02/13/2011 10:21 AM, Dennis Jacobfeuerborn wrote: Could you then pause the virtual machine and safely take an LVM snapshot, continue the VM and then mount the snapshot on the host and do a backup? Probably not. If you pause the guest then the filesystem on it might be in an inconsistent state. You will be able to make a snapshot since that happens on the block level but you might have problems mounting it. Regards, Dennis I've heard of somebody doing something to make this work. I think you could create another LV (from inside the VM - assuming a linux VM) on top of whatever raw partition was available to the VM. Then you could take the snapshot within the VM (which I believe guarantees that the filesystem is sync'ed when the snapshot is taken.) Then you use losetup and lvscan to make the lvm vg available on the host and I think you could access the snapshot without even pausing the vm. Nataraj I guess this is not the case. You can attach the VM virtual disk to the loopback and see the VG and it's LV's, but they show up as unavailable. I guess changing the snapshot to be available would be writing to the LV structure and could cause corruption while the vm is running, so better not. Nataraj ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
