Re: Amount of memory in buffers shown by the free command
On 15 May 2013 17:00, Michael MacIsaac mike...@us.ibm.com wrote: Does anyone know why free shows a different amount of cached memory that /proc/meminfo? For example: It's documented that Cached: in /proc/meminfo does not include swap cache, while the value from free does. But there's still differences from what I can tell, beyond the changes that happen in the second between the two commands. If I had time, I would certainly look in the source where both get their numbers and why they are different (which is more reliable than google with stackoverflow :-). -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Putting devices offline automatically
Mauro Souza writes: Hi guys, I have a client with a peculiar problem. They have zVM 4 partitions, sharing the same LCU's, every partition sees every DASD, and each partition have its own range of disks, defined with Offline_at_IPL on SYSTEM CONFIG. They use this setup because some times they need to access in one partition a disk belonging to another. When this need arises, they issue a VARY ON 2345 and get the disk online, use it, copy something, VARY OFF 2345. Works fine. The problem: some channels are getting offline sometimes. We know that people are always messing with the cables, and from time to time one fiber or another gets loose, they fix, and so on. And when the device comes back online, every single DASD on that CHPID comes online too, ignoring the Offline_at_IPL statement. As it should, because Offline_at_IPL is just for IPL. We are thinking on a method and apparatus for getting those DASDs offline when the CHPID gets back to life. I already have a REXX (I just deleted a lot of lines of CPSYNTAX and added a few more) that parses SYSTEM CONFIG and looks if a given DASD is in the Offline_at_IPL range, and can put a DASD offline. I just could not make the exec run by itself (or by MAINT, or another CMS machine) every time a channel status changes. I tried to setup PROP, and it looks fine, except it doesn't react at all. My PROP RTABLE is configured to run my exec, but when the channel gets back, it does nothing. If I send the message by hand from MAINT, the exec runs, and puts the device offline if it is on Offline_at_IP range. I guess I will have to read everything about PROP again (I could find few documentation and examples), in case I have missed something. I saw the NOTACCEPTed statement for DEVICES on SYSTEM CONFIG, but looks like it will take the device offline forever, and we will need to bring it online sometimes. Does anyone have any idea for us? NOTACCEPTED is reversible: provided you have# FEATURES ENABLE SET_DEVICES in your SYSTEM CONFIG, you could try doing CP VARY OFFLINE rdev CP SET DEVICES NOTACCEPTED rdev and see if that prevents the disappearance/reappearance of the channel triggering it coming online again. The CP Commands and Utilities Reference describes the behaviour as: NOTACCEPTed tells CP not to accept the specified device or devices when the device(s) is dynamically added to VM from another partition. When VM is running second level it will prevent a device(s) from being accepted when a device is attached to the virtual machine in which VM is running. If VM dynamically defines a device for its own partition the NOTACCEPTed designation is overridden. and it's not completely clear to me which case is covered by channel reappears. Worth a try though. Bringing it online again, you should only need a CP VARY ONLINE rdev CP still will retain some knowledge of the device though, so if that doesn't work and you want CP to forget about it even more (though still not entirely), you could try CP VARY OFFLINE rdev CP SET RDEVICE rdev CLEAR CP SET DEVICES NOTSENSED rdev CP SET DEVICES NOTACCEPTED rdev After that lot, to bring it back with default DASD options you'll want something like CP SET DEVICES SENSED rdev CP VARY ONLINE rdev or, if you want non-default settings for the rdev's setting of SHARED, EQID or MDC, you'll need instead an explicit CP SET RDEVICE rdev ... TYPE DASD ... which includes your options, followed by CP VARY ONLINE rdev (maybe preceded by CP SET DEVICES ACCEPTED rdev CP SET DEVICES SENSED rdev for the sake of completeness). --Malcolm -- Malcolm Beattie Mainframe Systems and Software Business, Europe IBM UK -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Missing lv
I used system-config-lvm to remove a lv “vg_rh62gfs/vg_swap”. It appeared to go ok and after zipling I rebooted only to get: dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap dracut: Skipping clustered volume group vg_snatest dracut: Skipping volume group vg_snatest dracut: inactive '/dev/vg_rh62gfs/lv_boot' [500.00 MiB] inherit dracut: inactive '/dev/vg_rh62gfs/lv_root' [2.12 GiB] inherit dracut: inactive '/dev/vg_rh62gfs/opt' [488.00 MiB] inherit dracut: One or more specified logical volume(s) not found. dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap I mounted the volumes on another system and did a scan to find where vg_swap was still specified. I couldn’t find any reference so I’m not sure why dracut wants to find it. Any suggestions? Neale -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Missing lv
/etc/fstab? On Thu, May 16, 2013 at 10:59 AM, Neale Ferguson ne...@sinenomine.net wrote: I used system-config-lvm to remove a lv “vg_rh62gfs/vg_swap”. It appeared to go ok and after zipling I rebooted only to get: dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap dracut: Skipping clustered volume group vg_snatest dracut: Skipping volume group vg_snatest dracut: inactive '/dev/vg_rh62gfs/lv_boot' [500.00 MiB] inherit dracut: inactive '/dev/vg_rh62gfs/lv_root' [2.12 GiB] inherit dracut: inactive '/dev/vg_rh62gfs/opt' [488.00 MiB] inherit dracut: One or more specified logical volume(s) not found. dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap I mounted the volumes on another system and did a scan to find where vg_swap was still specified. I couldn’t find any reference so I’m not sure why dracut wants to find it. Any suggestions? Neale -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- -- R; -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Missing lv
Nope On 5/16/13 11:02 AM, Rick Troth r...@casita.net wrote: /etc/fstab? -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
/dev/urandom issue that was fixed in suse kernel version 3.0.74
We ran into this issue and are rolling out the fix provided by Novell. Novell was telling us that it was due to a large number of ssh logins to a host but this does not always seem to be the case. Anyone have a more definitive reason for what caused the error and how it was fixed? Chris Will The information contained in this communication is highly confidential and is intended solely for the use of the individual(s) to whom this communication is directed. If you are not the intended recipient, you are hereby notified that any viewing, copying, disclosure or distribution of this information is prohibited. Please notify the sender, by electronic mail or telephone, of any unintended receipt and delete the original message without making any copies. Blue Cross Blue Shield of Michigan and Blue Care Network of Michigan are nonprofit corporations and independent licensees of the Blue Cross and Blue Shield Association. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Amount of memory in buffers shown by the free command
Alex and Rob, Thanks for the replies. It looks like the buffers value shown by free on SLES is the the sum of the Cached and SReclaimable values from /proc/meminfo/, while on RHEL it is just Cached. On SLES: # egrep '^Cached|^SRe' /proc/meminfo;free Cached: 130336 kB SReclaimable: 17576 kB total used free sharedbuffers cached Mem: 1020416 318156 702260 0 11688 147912 ... On RHEL: # egrep '^Cached|^SRe' /proc/meminfo;free Cached:36668 kB SReclaimable: 25828 kB total used free sharedbuffers cached Mem:245772 234828 10944 0 95568 36668 ... Mike MacIsaac mikemac at-sign us.ibm.com -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Missing lv
Hi Neale, On 05/16/2013 04:59 PM, Neale Ferguson wrote: I used system-config-lvm to remove a lv “vg_rh62gfs/vg_swap”. It appeared to go ok and after zipling I rebooted only to get: dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap dracut: Skipping clustered volume group vg_snatest dracut: Skipping volume group vg_snatest dracut: inactive '/dev/vg_rh62gfs/lv_boot' [500.00 MiB] inherit dracut: inactive '/dev/vg_rh62gfs/lv_root' [2.12 GiB] inherit dracut: inactive '/dev/vg_rh62gfs/opt' [488.00 MiB] inherit dracut: One or more specified logical volume(s) not found. dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap I mounted the volumes on another system and did a scan to find where vg_swap was still specified. I couldn’t find any reference so I’m not sure why dracut wants to find it. Do you happen to have this in your kernel command line?: rd_LVM_LV=vg_rh62gfs/lv_swap One should only ever have dependencies for the root-fs on the dracut command line [1,2]. Swap does not belong to the root-fs dependencies; swap is only activated later on during the sysVinit process after the root-fs was already mounted by the initramfs. Also, it might make dracut insist on finding and activating this particular LV and thus breaks when it's gone. [1] https://www.kernel.org/pub/linux/utils/boot/dracut/dracut.html#_lvm [2] https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/ap-s390info.html#ap-s390info-Adding_DASDs-Persistently_setting_online-Part_of_root_file_system HTH Steffen Linux on System z Development IBM Deutschland Research Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Putting devices offline automatically
Hi Malcolm! We tried the setup you suggested, and worked as we wanted it! Thanks! Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/5/16 Malcolm Beattie beatt...@uk.ibm.com Mauro Souza writes: Hi guys, I have a client with a peculiar problem. They have zVM 4 partitions, sharing the same LCU's, every partition sees every DASD, and each partition have its own range of disks, defined with Offline_at_IPL on SYSTEM CONFIG. They use this setup because some times they need to access in one partition a disk belonging to another. When this need arises, they issue a VARY ON 2345 and get the disk online, use it, copy something, VARY OFF 2345. Works fine. The problem: some channels are getting offline sometimes. We know that people are always messing with the cables, and from time to time one fiber or another gets loose, they fix, and so on. And when the device comes back online, every single DASD on that CHPID comes online too, ignoring the Offline_at_IPL statement. As it should, because Offline_at_IPL is just for IPL. We are thinking on a method and apparatus for getting those DASDs offline when the CHPID gets back to life. I already have a REXX (I just deleted a lot of lines of CPSYNTAX and added a few more) that parses SYSTEM CONFIG and looks if a given DASD is in the Offline_at_IPL range, and can put a DASD offline. I just could not make the exec run by itself (or by MAINT, or another CMS machine) every time a channel status changes. I tried to setup PROP, and it looks fine, except it doesn't react at all. My PROP RTABLE is configured to run my exec, but when the channel gets back, it does nothing. If I send the message by hand from MAINT, the exec runs, and puts the device offline if it is on Offline_at_IP range. I guess I will have to read everything about PROP again (I could find few documentation and examples), in case I have missed something. I saw the NOTACCEPTed statement for DEVICES on SYSTEM CONFIG, but looks like it will take the device offline forever, and we will need to bring it online sometimes. Does anyone have any idea for us? NOTACCEPTED is reversible: provided you have# FEATURES ENABLE SET_DEVICES in your SYSTEM CONFIG, you could try doing CP VARY OFFLINE rdev CP SET DEVICES NOTACCEPTED rdev and see if that prevents the disappearance/reappearance of the channel triggering it coming online again. The CP Commands and Utilities Reference describes the behaviour as: NOTACCEPTed tells CP not to accept the specified device or devices when the device(s) is dynamically added to VM from another partition. When VM is running second level it will prevent a device(s) from being accepted when a device is attached to the virtual machine in which VM is running. If VM dynamically defines a device for its own partition the NOTACCEPTed designation is overridden. and it's not completely clear to me which case is covered by channel reappears. Worth a try though. Bringing it online again, you should only need a CP VARY ONLINE rdev CP still will retain some knowledge of the device though, so if that doesn't work and you want CP to forget about it even more (though still not entirely), you could try CP VARY OFFLINE rdev CP SET RDEVICE rdev CLEAR CP SET DEVICES NOTSENSED rdev CP SET DEVICES NOTACCEPTED rdev After that lot, to bring it back with default DASD options you'll want something like CP SET DEVICES SENSED rdev CP VARY ONLINE rdev or, if you want non-default settings for the rdev's setting of SHARED, EQID or MDC, you'll need instead an explicit CP SET RDEVICE rdev ... TYPE DASD ... which includes your options, followed by CP VARY ONLINE rdev (maybe preceded by CP SET DEVICES ACCEPTED rdev CP SET DEVICES SENSED rdev for the sake of completeness). --Malcolm -- Malcolm Beattie Mainframe Systems and Software Business, Europe IBM UK -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Missing lv
You should take a look on your initrd too. Maybe the lv_swap is still referenced there. Try recreating it to see if the ghost lv vanishes for good. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/5/16 Steffen Maier ma...@linux.vnet.ibm.com Hi Neale, On 05/16/2013 04:59 PM, Neale Ferguson wrote: I used system-config-lvm to remove a lv “vg_rh62gfs/vg_swap”. It appeared to go ok and after zipling I rebooted only to get: dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap dracut: Skipping clustered volume group vg_snatest dracut: Skipping volume group vg_snatest dracut: inactive '/dev/vg_rh62gfs/lv_boot' [500.00 MiB] inherit dracut: inactive '/dev/vg_rh62gfs/lv_root' [2.12 GiB] inherit dracut: inactive '/dev/vg_rh62gfs/opt' [488.00 MiB] inherit dracut: One or more specified logical volume(s) not found. dracut: Scanning devices dasda1 dasdb1 dasdc1 for LVM logical volumes vg_rh62gfs/lv_root vg_rh62gfs/lv_swap I mounted the volumes on another system and did a scan to find where vg_swap was still specified. I couldn’t find any reference so I’m not sure why dracut wants to find it. Do you happen to have this in your kernel command line?: rd_LVM_LV=vg_rh62gfs/lv_swap One should only ever have dependencies for the root-fs on the dracut command line [1,2]. Swap does not belong to the root-fs dependencies; swap is only activated later on during the sysVinit process after the root-fs was already mounted by the initramfs. Also, it might make dracut insist on finding and activating this particular LV and thus breaks when it's gone. [1] https://www.kernel.org/pub/**linux/utils/boot/dracut/** dracut.html#_lvmhttps://www.kernel.org/pub/linux/utils/boot/dracut/dracut.html#_lvm [2] https://access.redhat.com/**site/documentation/en-US/Red_** Hat_Enterprise_Linux/6/html/**Installation_Guide/ap-** s390info.html#ap-s390info-**Adding_DASDs-Persistently_** setting_online-Part_of_root_**file_systemhttps://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Installation_Guide/ap-s390info.html#ap-s390info-Adding_DASDs-Persistently_setting_online-Part_of_root_file_system HTH Steffen Linux on System z Development IBM Deutschland Research Development GmbH Vorsitzende des Aufsichtsrats: Martina Koederitz Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 --**--**-- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/**wlvindex?LINUX-390http://www.marist.edu/htbin/wlvindex?LINUX-390 --**--**-- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Missing lv
That was it Steffen. I did a find / grep looking for vg_swap so I thought it'd pick up the zipl.conf but I must have messed up the command. In any event, I got rid of it and re-ran zipl. Note, that rd_LVM wasn't put in manually by me but as part of the installation. Many thanks... Neale On 5/16/13 1:39 PM, Steffen Maier ma...@linux.vnet.ibm.com wrote: Do you happen to have this in your kernel command line?: rd_LVM_LV=vg_rh62gfs/lv_swap -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: /dev/urandom issue that was fixed in suse kernel version 3.0.74
On 5/16/2013 10:15 AM, Will, Chris wrote: We ran into this issue and are rolling out the fix provided by Novell. Novell was telling us that it was due to a large number of ssh logins to a host but this does not always seem to be the case. Anyone have a more definitive reason for what caused the error and how it was fixed? The ssh thing is just a way to recreate the problem. It's really just a matter of multiple simultaneous users of /dev/urandon and ssh was one way to do it. I was able to recreate it with: #!/bin/sh for ((c=0; c 32; c++)) do for ((i=0; i 256; i++)) do dd if=/dev/urandom of=/dev/null bs=1 count=4096 /dev/null 21 done done dd if=/dev/urandom of=/dev/null bs=1 count=1 21 | grep -q '0 bytes' echo badness exit -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Amount of memory in buffers shown by the free command
Mike Rob, That is not what I see at my end. Below are sample of RHEL 5.9 and RHEL 6.3. In both cases, the number of cached from the 'free' command matches to the number of cached found in /proc/meminfo. Strange but true.. $ cat /etc/*se Red Hat Enterprise Linux Server release 6.3 (Santiago) $ egrep '^Cached|^SRe' /proc/meminfo;free Cached: 2082876 kB SReclaimable: 287328 kB total used free sharedbuffers cached Mem: 39785363879060 99476 0 5514522082876 -/+ buffers/cache:12447322733804 Swap: 1199784 39201195864 $ cat /etc/*se Red Hat Enterprise Linux Server release 5.9 (Tikanga) $ egrep '^Cached|^SRe' /proc/meminfo;free Cached:4940460 kB total used free sharedbuffers cached Mem: 10290680 10013064 277616 0 7163724940460 -/+ buffers/cache:43562325934448 Swap: 2135672 83162127356 Alex Suthammanont -Original Message- From: Linux on 390 Port [mailto:LINUX-390@vm.marist.edu] On Behalf Of Michael MacIsaac Sent: Thursday, May 16, 2013 1:10 PM To: LINUX-390@vm.marist.edu Subject: Re: Amount of memory in buffers shown by the free command Alex and Rob, Thanks for the replies. It looks like the buffers value shown by free on SLES is the the sum of the Cached and SReclaimable values from /proc/meminfo/, while on RHEL it is just Cached. On SLES: # egrep '^Cached|^SRe' /proc/meminfo;free Cached: 130336 kB SReclaimable: 17576 kB total used free sharedbuffers cached Mem: 1020416 318156 702260 0 11688 147912 ... On RHEL: # egrep '^Cached|^SRe' /proc/meminfo;free Cached:36668 kB SReclaimable: 25828 kB total used free sharedbuffers cached Mem:245772 234828 10944 0 95568 36668 ... Mike MacIsaac mikemac at-sign us.ibm.com -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- This message, and any attachments, is for the intended recipient(s) only, may contain information that is privileged, confidential and/or proprietary and subject to important terms and conditions available at http://www.bankofamerica.com/emaildisclaimer. If you are not the intended recipient, please delete this message. -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
