Re: RAID6 mdadm --grow bug?
On Thursday September 13, [EMAIL PROTECTED] wrote: > Neil, > > On RHEL5 the kernel is 2.6.18-8.1.8. On Ubuntu 7.04 the kernel is > 2.6.20-16. Someone on the Arstechnica forums wrote they see the same > thing in Debian etch running kernel 2.6.18. Below is a messages log > from the RHEL5 system. I have only included the section for creating > the RAID6, adding a spare and trying to grow it. There is a one line > error when I do the "mdadm --grow" command. It is "md: couldn't > update array info. -22." reshaping raid6 arrays was not supported until 2.6.21. So you'll need a newer kernel. NeilBrown - 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: RAID6 mdadm --grow bug?
Neil, On RHEL5 the kernel is 2.6.18-8.1.8. On Ubuntu 7.04 the kernel is 2.6.20-16. Someone on the Arstechnica forums wrote they see the same thing in Debian etch running kernel 2.6.18. Below is a messages log from the RHEL5 system. I have only included the section for creating the RAID6, adding a spare and trying to grow it. There is a one line error when I do the "mdadm --grow" command. It is "md: couldn't update array info. -22." md: bind md: bind md: bind md: bind md: md0: raid array is not clean -- starting background reconstruction raid5: device loop4 operational as raid disk 3 raid5: device loop3 operational as raid disk 2 raid5: device loop2 operational as raid disk 1 raid5: device loop1 operational as raid disk 0 raid5: allocated 4204kB for md0 raid5: raid level 6 set md0 active with 4 out of 4 devices, algorithm 2 RAID5 conf printout: --- rd:4 wd:4 fd:0 disk 0, o:1, dev:loop1 disk 1, o:1, dev:loop2 disk 2, o:1, dev:loop3 disk 3, o:1, dev:loop4 md: syncing RAID array md0 md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc. md: using maximum available idle IO bandwidth (but not more than 20 KB/sec) for reconstruction. md: using 128k window, over a total of 102336 blocks. md: md0: sync done. RAID5 conf printout: --- rd:4 wd:4 fd:0 disk 0, o:1, dev:loop1 disk 1, o:1, dev:loop2 disk 2, o:1, dev:loop3 disk 3, o:1, dev:loop4 md: bind md: couldn't update array info. -22 David. On Sep 13, 2007, at 3:52 AM, Neil Brown wrote: On Wednesday September 12, [EMAIL PROTECTED] wrote: Problem: The mdadm --grow command fails when trying to add disk to a RAID6. .. So far I have replicated this problem on RHEL5 and Ubuntu 7.04 running the latest official updates and patches. I have even tried it with the most latest version of mdadm 2.6.3 under RHEL5. RHEL5 uses version 2.5.4. You don't say what kernel version you are using (as I don't use RHEL5 or Ubunutu, I don't know what 'latest' means). If it is 2.6.23-rcX, then it is a known problem that should be fixed in the next -rc. If it is something else... I need details. Also, any kernel message (run 'dmesg') might be helpful. NeilBrown - 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: RAID6 mdadm --grow bug?
On Wednesday September 12, [EMAIL PROTECTED] wrote: > > > Problem: > > The mdadm --grow command fails when trying to add disk to a RAID6. > .. > > So far I have replicated this problem on RHEL5 and Ubuntu 7.04 > running the latest official updates and patches. I have even tried it > with the most latest version of mdadm 2.6.3 under RHEL5. RHEL5 uses > version 2.5.4. You don't say what kernel version you are using (as I don't use RHEL5 or Ubunutu, I don't know what 'latest' means). If it is 2.6.23-rcX, then it is a known problem that should be fixed in the next -rc. If it is something else... I need details. Also, any kernel message (run 'dmesg') might be helpful. NeilBrown - 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
RAID6 mdadm --grow bug?
Problem: The mdadm --grow command fails when trying to add disk to a RAID6. The man page says it can do this. "GROW MODE The GROW mode is used for changing the size or shape of an active array. For this to work, the kernel must support the necessary change. Various types of growth are being added dur- ing 2.6 development, including restructuring a raid5 array to have more active devices. Currently the only support available is to · change the "size" attribute for RAID1, RAID5 and RAID6. · increase the "raid-disks" attribute of RAID1, RAID5, and RAID6. · add a write-intent bitmap to any array which supports these bitmaps, or remove a write- intent bitmap from such an array. " So far I have replicated this problem on RHEL5 and Ubuntu 7.04 running the latest official updates and patches. I have even tried it with the most latest version of mdadm 2.6.3 under RHEL5. RHEL5 uses version 2.5.4. How to replicate the problem: You can either use real physical disks or use the loopback device to create fake disks. Here are the steps using the loopback method as root. cd /tmp dd if=/dev/zero of=rd1 bs=10240 count=10240 cp rd1 rd2;cp rd1 rd3;cp rd1 rd4;cp rd1 rd5 losetup /dev/loop1 rd1;losetup /dev/loop2 rd2;losetup /dev/loop3 rd3;losetup /dev/loop4 rd4;losetup /dev/loop5 rd5 mdadm --create --verbose /dev/md0 --level=6 --raid-devices=4 /dev/ loop1 /dev/loop2 /dev/loop3 /dev/loop4 At this point wait a minute while the raid is being built. mdadm --add /dev/md0 /dev/loop5 mdadm --grow /dev/md0 --raid-devices=5 You should get the following error mdadm: Need to backup 384K of critical section.. mdadm: Cannot set device size/shape for /dev/md0: Invalid argument How to clean up mdadm --stop /dev/md0 mdadm --remove /dev/md0 losetup -d /dev/loop1;losetup -d /dev/loop2;losetup -d /dev/ loop3;losetup -d /dev/loop4;losetup -d /dev/loop5 rm rd1 rd2 rd3 rd4 rd5 David. - 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
