Hi Martin, On Sat, Sep 14, 2013 at 10:43 PM, Martin Wilck <mwilck@xxxxxxxx> wrote: > On 09/14/2013 05:06 PM, Francis Moreau wrote: >> Martin, >> >> On Sat, Sep 14, 2013 at 4:33 PM, Francis Moreau <francis.moro@xxxxxxxxx> wrote: >>> On Sat, Sep 14, 2013 at 12:38 PM, NeilBrown <neilb@xxxxxxx> wrote: >>>> On Sat, 14 Sep 2013 00:35:47 +0200 Francis Moreau <francis.moro@xxxxxxxxx> >>>> wrote: >> >> [...] >> >>>> >>>> BTW I think I've fixed the issue with mdadm -R /dev/md125 for DDF. >>>> Try the latest git. >>> >>> It seems it fixes the issue: mdmon is now correctly started with a >>> degraded DDF array. >>> >>> However, after using the system with only one disk (sda), sdb is now >>> outdated. I rebooted the system with 2 disks but mdadm doesn't seem to >>> notice that sdb is outdated: >>> >>> # mdadm -I /dev/sda >>> mdadm: container /dev/md/ddf0 now has 1 device >>> mdadm: /dev/md/array1_0 assembled with 1 device but not started >>> # mdadm -I /dev/sdb >>> mdadm: container /dev/md/ddf0 now has 2 devices >>> mdadm: Started /dev/md/array1_0 with 2 devices (1 new) >>> # cat /proc/mdstat >>> Personalities : [raid1] >>> md126 : active (auto-read-only) raid1 sdb[1] sda[0] >>> 2064384 blocks super external:/md127/0 [2/2] [UU] >>> >>> md127 : inactive sdb[1](S) sda[0](S) >>> 65536 blocks super external:ddf >>> >>> So this time mdadm fails to kick out non fresh disk (when using '-I') >>> but with DDF. >>> >> >> Maybe you have an idea on why mdadm doesn't notice that sdb is >> outdated in that case (DDF) ? > > It's a bug. I am sending a patch soon. Thanks a lot. > I did give your patch "DDF: compare_super_ddf: fix sequence number check" a try and now mdadm is able to detect a difference between the 2 disks. Therefore it refuses to insert the second disk which is better. However it's still not able to detect which version is the "fresher" like mdadm does with soft RAID1 (metadata 1.2). Therefore mdadm is not able to kick out the first disk if it's the outdated one. Is that expected ? -- Francis -- 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
