Re: Raid over 48 disks ... for real now
On Thu, 17 Jan 2008, Janek Kozicki wrote: I wish RHEL would support XFS/ZFS, but for now, I'm stuck with ext3. there is ext4 (or ext4dev) - it's an ext3 modified to support 1024 PB size (1048576 TB). You could check if it's feasible. Personally I'd always stick with ext2/ext3/ext4 since it is most widely used and thus has the best recovery tools. Something else to keep in mind...XFS fs repair tools require large amounts of memory. If you were to create one or a few really huge fs's on this array, you might end up with fs's which can't be repaired because you don't have or even can't get a machine with enough RAM for the job...not to mention the amount of time it would take. -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Monitoring hardware raid
On Mon, 2 Oct 2006, Mauricio Tavares wrote: I have here a full tower full of drives that is a self-standing hardware raid which is connected to a redhat 9 box through a scsi cable. With hardware SCSI-attached RAID, odds are, if there are any monitoring utilities, they'll be proprietary to that hardware RAID device, so you'll need to see if the manufacturer has tools for Linux, or search the net and see if any 3rd party has figured out how to talk to the device. -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
changing MD device names
I have a system which was running several raid1 devices (md0 - md2) using 2 physical drives (hde, and hdg). I wanted to swap out these drives for two different ones, so I did the following: 1) swap out hdg for a new drive 2) create degraded raid1's (md3 and md4) using partitions on new hdg 3) format md3 and md4 and copy data from md0-2 to md3-4 4) install grub on new hdg 5) pull hde Now, after a bit of fixing in the grub menu and fstab, I have a system that boots up using just 1 of the new drives, but the md devices are md3 and md4. What's the easiest way to change the prefered minor # and get these to be md0 and md1? Will just booting from a rescue or live CD and assembling the new drives as md0 md1 automatically update the prefered minor in their superblocks? The system is running Centos 4 (2.6.9-34.0.1.EL kernel). -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Two-disk RAID5?
On Wed, 26 Apr 2006, John Rowe wrote: I'm about to create a RAID1 file system and a strange thought occurs to me: if I create a two-disk RAID5 array then I can grow it later by the simple expedient of adding a third disk and hence doubling its size. No. When one of the 2 drives in your RAID5 dies, and all you have for some blocks is parity info, how will the missing data be reconstructed? You could [I suspect] create a 2 disk RAID5 in degraded mode (3rd member missing), but it'll obviously lack redundancy until you add a 3rd disk, which won't add anything to your RAID5 storage capacity. -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Two-disk RAID5?
On Wed, 26 Apr 2006, Jansen, Frank wrote: It is not possible to flip a bit to change a set of disks from RAID 1 to RAID 5, as the physical layout is different. As Tuomas pointed out though, a 2 disk RAID5 is kind of a special case where all you have is data and parity which is actually also just data. Seems kind of like a RAID1 with extra overhead. I don't think I've ever heard of a RAID5 implementation willing to handle 3 drives though. I suspect I should have just kept out of this, and waited for someone like Neil to answer authoratatively. So...Neil, what's the right answer to Tuomas's 2 disk RAID5 question? :) -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Recommendations for supported 4-port SATA PCI card ?
I've got several systems with pairs of Promise Technology, Inc. PDC20318 (SATA150 TX4) and no problems other than lack of support in the install kernels back when we got them (about a year and a half ago). -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
confused raid1
I've inheritted responsibility for a server with a root raid1 that degrades every time the system is rebooted. It's a 2.4.x kernel. I've got both raidutils and mdadm available. The raid1 device is supposed to be /dev/hde1 /dev/hdg1 with /dev/hdc1 as a spare. I believe it was created with raidutils and the following portion of /etc/raidtab: raiddev /dev/md1 raid-level 1 nr-raid-disks 2 chunk-size 64k persistent-superblock 1 nr-spare-disks 1 device /dev/hde1 raid-disk 0 device /dev/hdg1 raid-disk 1 device /dev/hdc1 spare-disk0 The output of mdadm -E concerns me though. # mdadm -E /dev/hdc1 /dev/hdc1: Magic : a92b4efc Version : 00.90.00 UUID : 8b65fa52:21176cc9:cbb74149:c418b5a4 Creation Time : Tue Jan 13 13:21:41 2004 Raid Level : raid1 Device Size : 30716160 (29.29 GiB 31.45 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 1 Update Time : Thu Aug 11 08:38:59 2005 State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : -1 Spare Devices : 0 Checksum : 6a4dddb8 - correct Events : 0.195 Number Major Minor RaidDevice State this 1 2211 active sync /dev/hdc1 0 0 3310 active sync /dev/hde1 1 1 2211 active sync /dev/hdc1 # mdadm -E /dev/hde1 /dev/hde1: Magic : a92b4efc Version : 00.90.00 UUID : 8b65fa52:21176cc9:cbb74149:c418b5a4 Creation Time : Tue Jan 13 13:21:41 2004 Raid Level : raid1 Device Size : 30716160 (29.29 GiB 31.45 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 1 Update Time : Mon Aug 15 11:16:43 2005 State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : -1 Spare Devices : 0 Checksum : 6a5348c9 - correct Events : 0.199 Number Major Minor RaidDevice State this 0 3310 active sync /dev/hde1 0 0 3310 active sync /dev/hde1 1 1 3411 active sync /dev/hdg1 # mdadm -E /dev/hdg1 /dev/hdg1: Magic : a92b4efc Version : 00.90.00 UUID : 8b65fa52:21176cc9:cbb74149:c418b5a4 Creation Time : Tue Jan 13 13:21:41 2004 Raid Level : raid1 Device Size : 30716160 (29.29 GiB 31.45 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 1 Update Time : Mon Aug 15 11:16:43 2005 State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : -1 Spare Devices : 0 Checksum : 6a5348cc - correct Events : 0.199 Number Major Minor RaidDevice State this 1 3411 active sync /dev/hdg1 0 0 3310 active sync /dev/hde1 1 1 3411 active sync /dev/hdg1 Shouldn't total devices be at least 2? How can failed devices be -1? When the system reboots, md1 becomes just /dev/hdc1. I've used mdadm to add hde1, fail and then remove hdc1, and add hdg1. How can I repair the array such that it will survive the next reboot and keep hde1 and hdg1 as the working devices? md1 : active raid1 hdg1[1] hde1[0] 30716160 blocks [2/2] [UU] -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: confused raid1
On Mon, 15 Aug 2005, Mario 'BitKoenig' Holbe wrote: Well, reading the kernel boot messages could help. Perhaps, the hdc1 partition is type fd (raid autodetect) and the driver for hd[eg] is not in place when the RAID Autodetection is running. I should have included that. All 3 of them are type fd. -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [OT] best tape backup system?
On Tue, 22 Feb 2005, Louis-David Mitterrand wrote: I am considering getting a Sony SAIT 3 with 500G/1TB tapes, which seems like a nice solution for backuping a whole server on a single tape. Has anyone used that hardware and can comment on its performance, linux-compatibility or otherwise? Is there a better solution out there? Better depends on what you want/need/can afford. Last time I was tape shopping, I thought this would be a good compromise on the need/can afford: Exabyte VXA-2 Packetloader 1x10 Native tape capacity is 800gb. The only downside is, no magazine...it stores the tapes in an internal carosel accessed from the front, one position at a time. For a bit more $, they have magazine based tape library systems with VXA-2 drives. Anyone used these? I'd still like one. -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [OT] best tape backup system?
On Tue, 22 Feb 2005, Alvin Oga wrote: Better depends on what you want/need/can afford. Last time I was tape shopping, I thought this would be a good compromise on the need/can afford: Exabyte VXA-2 Packetloader 1x10 Native tape capacity is 800gb. The only downside is, no magazine...it stores the tapes in an internal carosel accessed from the front, one position at a time. For a bit more $, they have magazine based tape library systems with VXA-2 drives. for 1TB of storage ... i'd put the data on 4 disks ( raided ) and take the disks and put in nice bubble wrap and nice cushion I should clarify, that's 80GB per tape...so 800GB native assumes you have 10 tapes in the unit. i keep wondering why people pay $150K for 1TB brandname tape subsystems .. I wouldn't pay that much...but I think the common wisdom is that tape is more durable/portable than disks. Once upon a time, it was cheaper than disks too...but that's no longer the case. It's part of why my plan to buy a bunch of Exabyte stuff got shot down and instead we bought P4's with 1TB SATA-RAID5 arrays to use as backup servers. -- Jon Lewis | I route Senior Network Engineer | therefore you are Atlantic Net| _ http://www.lewis.org/~jlewis/pgp for PGP public key_ - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
