On Fri, 2012-08-31 at 21:21 -0700, Ross Boylan wrote: > On Fri, 2012-08-31 at 11:46 +1000, Adam Goryachev wrote: > > On 31/08/12 10:48, Ross Boylan wrote: > > > /dev/md1 was RAID 1 built from hda3 and hdb3. After increasing the > > > partition size of hd[ab]3, md1 could not be assembled. I think I > > > understand why and have a solution, but I would appreciate it if > > > someone could check it. This is with 0.90 format on Debian Lenny with > > > the partitions in raid auto-detect mode. hda and hdb are virtual > > > disks inside a kvm VM; it would be time-consuming to rebuild it from > > > scratch. > > > > > > The final wrinkle is that when I brought the VM up and dm1 was not > > > constructed one of the partitions was used anyway, so they are now out > > > of sync. > > > > > > Analysis: Growing the partitions meant that the mdadm superblocks were > > > not at the expected offset from the end of the partitions, and so they > > > weren't recognized as part of the array. [description of a possible solution and problems preserving the UUID when using mdadm in squeeze deleted] Since the more recent mdadm insisted on tweaking my uuid with a home host, I did it from early in the boot process for the lenny VM. Set the break=mount option for system startup. This is a Debianism, I think. It also requires the use of an initrd. This drops you into a shell. modprobe md # essential #lenny uses hda not sda for disk name mdadm --create /dev/md1 --uuid=6f05ff4e:b4d49c1f:7fa21d88:ad0c50a9 =0.90 --level=mirror --raid-devices=2 /dev/hdb3 missing mdadm --manage /dev/md1 --add /dev/hda3 mdadm --wait /dev/md1 Restarted the VM (not sure if necessary). Although mdadm has some commands for --grow'ing the size of the md, I did not need to use any of them. Possibly that's because I used RAID1. Can anyone comment? For completeness, the final steps were pvresize /dev/md1 # makes the PV fill the whole md1 lvextend -L+1G myvg/usr # grow an LV that needed more room resize2fs /dev/myvg/usr # online resize of filesystem This is for ext3 on top of LVM on top of RAID. Ross -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
