On Saturday 23 May 2009 23:05:35 NeilBrown wrote: > On Sun, May 24, 2009 1:03 am, rdc wrote: > > Yesterday i grew my 4*500GB raid5 array to 7*500GB. The reshape operation > > ended succesfully according to the logs : > > > > May 22 22:24:56 [kernel] md: md2: reshape done. > > May 22 22:24:56 [kernel] RAID5 conf printout: > > May 22 22:24:56 [kernel] --- rd:7 wd:7 > > May 22 22:24:56 [kernel] disk 0, o:1, dev:dm-3 > > May 22 22:24:56 [kernel] disk 1, o:1, dev:dm-0 > > May 22 22:24:56 [kernel] disk 2, o:1, dev:dm-2 > > May 22 22:24:56 [kernel] disk 3, o:1, dev:dm-1 > > May 22 22:24:56 [kernel] disk 4, o:1, dev:dm-8 > > May 22 22:24:56 [kernel] disk 5, o:1, dev:dm-6 > > May 22 22:24:56 [kernel] disk 6, o:1, dev:dm-5 > > The devices in your array are dm-xx devices, but.... > > > However, upon restarting this morning the grown array was no longer > > detected, > > and my investigation revealed that the 3 device that were added do not > > contain > > an md superblock at all ! > > > > One of the 3 new devices : > > mdadm --examine -v /dev/sdb1 > > mdadm: No md superblock detected on /dev/sdb1. > > ... you are looking on sdxx devices for the superblock. This > seem to me to be a strange thing to do. > What does > mdadm --example /dev/mapper/whatever > show? mdadm --examine -v /dev/mapper/sdb1 mdadm: No md superblock detected on /dev/mapper/sdb1 > > What exactly are the dm-xx devices? Well the dm-xx devices are just the same partitions mapped into dm by the mapper. It just creates /dev/mapper/sdXX devices which are the same as the underlying /dev/sdxx devices. I removed the mappings for clarity. The names always show up as dm-XX from a kernel perspective. > > NeilBrown -- 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
