Bug#538843: mdadm 3 fails to assemble root array

Jeff King peff at peff.net
Mon Jul 27 12:17:20 UTC 2009


Package: mdadm
Version: 3.0-2
Severity: normal

Since upgrading to mdadm 3, my system fails to assemble the root raid1
array. The raid1 module is loaded properly, but running "mdadm
--assemble --scan --run" fails. It produces no error message, but exits
with status code '2' (which I determined by dropping to the shell after
it failed and running the command manually).

Reinstalling (and rebuilding the initrd with) the version of mdadm from
testing (2.6.9-3) works fine.

I was, however, able to get it to work by regenerating the mdadm.conf
via "mdadm --examine --scan". The original mdadm.conf (which works just
fine with mdadm 2.6.9-3) contains:

ARRAY /dev/md0 level=raid1 num-devices=1 UUID=7e9d311e:35f7cf78:328c150d:a274a3d1

But the newly generated conf contains:

ARRAY /dev/md0 UUID=7e9d311e:35f7cf78:038d364c:261108ae

Note that the UUIDs are the same in the first half, but totally
different in the second half. One other thing to note is that
"num-devices=1" is no longer true. The raid was created with a single
device, and then grown to contain an additional device.

So my problem has been resolved, but I am not sure whether there is a
bug that will affect other users (hence this bug report). Why is it that
2.6.9 works with one UUID, but mdadm 3 requires another?

Or has my UUID been screwed up all along, and 2.6.9 never cared? In that
case, it would be nice for the mdadm 3 postinst to double-check, since
the situation leads to an unbootable system.

-- Package-specific info:
--- mount output
/dev/md0 on / type ext3 (rw,noatime,acl,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
//segfault/shared on /mnt/segfault type cifs (rw,mand)

--- mdadm.conf
# mdadm.conf
#
# Please refer to mdadm.conf(5) for information about this file.
#

# by default, scan all partitions (/proc/partitions) for MD superblocks.
# alternatively, specify devices to scan, using wildcards if desired.
DEVICE partitions

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes

# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays
ARRAY /dev/md0 level=raid1 num-devices=1 UUID=7e9d311e:35f7cf78:328c150d:a274a3d1

# This file was auto-generated on Tue, 17 Feb 2009 00:40:51 -0500
# by mkconf $Id$

--- /proc/mdstat:
Personalities : [raid1] 
md0 : active raid1 sda2[0] sdb2[1]
      243216000 blocks [2/2] [UU]
      
unused devices: <none>

--- /proc/partitions:
major minor  #blocks  name

   8       16  244198584 sdb
   8       17     979933 sdb1
   8       18  243216067 sdb2
   8        0  244198584 sda
   8        1     979933 sda1
   8        2  243216067 sda2
   9        0  243216000 md0

--- initrd.img-2.6.30-1-686:
35445 blocks
6b782ae76f866914ec236b2d14b43f24  ./scripts/local-top/mdadm
631197f411730b971f92a664067c0f00  ./lib/modules/2.6.30-1-686/kernel/drivers/md/raid10.ko
749043015b593c49b8ae66d40c9f2209  ./lib/modules/2.6.30-1-686/kernel/drivers/md/raid456.ko
0a0ed11b6525a6169c5af3a1c3997208  ./lib/modules/2.6.30-1-686/kernel/drivers/md/multipath.ko
cecf3a05e9db5bd47cb8078fceb47b9b  ./lib/modules/2.6.30-1-686/kernel/drivers/md/raid6_pq.ko
19cb9d282089fe9407740dd6c26506c8  ./lib/modules/2.6.30-1-686/kernel/drivers/md/raid0.ko
5f6e41140d5212bb53084e996436f770  ./lib/modules/2.6.30-1-686/kernel/drivers/md/raid1.ko
74d1be0689710642e8abf47339ef46d1  ./lib/modules/2.6.30-1-686/kernel/drivers/md/linear.ko
5ab81ebdcfc5459cb55b22b054987b35  ./lib/modules/2.6.30-1-686/kernel/drivers/md/md-mod.ko
659e311440cd69e7736d077561faa8fa  ./lib/modules/2.6.30-1-686/kernel/drivers/video/console/mdacon.ko
0363e9034d1066e8e2002781401c547d  ./etc/mdadm/mdadm.conf
6e7bc5a5bed9c9fee0cabf27e8543b97  ./sbin/mdadm

--- /proc/modules:
raid1 18476 1 - Live 0xf83f4000
md_mod 77772 2 raid1, Live 0xf83d3000

--- /var/log/syslog:

--- volume detail:
/dev/hda is not recognised by mdadm.
/dev/sda is not recognised by mdadm.
/dev/sda1 is not recognised by mdadm.
/dev/sda2:
          Magic : a92b4efc
        Version : 0.90.00
           UUID : 7e9d311e:35f7cf78:038d364c:261108ae
  Creation Time : Tue Feb 17 00:30:43 2009
     Raid Level : raid1
  Used Dev Size : 243216000 (231.95 GiB 249.05 GB)
     Array Size : 243216000 (231.95 GiB 249.05 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Mon Jul 27 07:58:49 2009
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 29e5a424 - correct
         Events : 570


      Number   Major   Minor   RaidDevice State
this     0       8        2        0      active sync   /dev/sda2

   0     0       8        2        0      active sync   /dev/sda2
   1     1       8       18        1      active sync   /dev/sdb2
--
/dev/sdb is not recognised by mdadm.
/dev/sdb1 is not recognised by mdadm.
/dev/sdb2:
          Magic : a92b4efc
        Version : 0.90.00
           UUID : 7e9d311e:35f7cf78:038d364c:261108ae
  Creation Time : Tue Feb 17 00:30:43 2009
     Raid Level : raid1
  Used Dev Size : 243216000 (231.95 GiB 249.05 GB)
     Array Size : 243216000 (231.95 GiB 249.05 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Mon Jul 27 07:58:49 2009
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 29e5a436 - correct
         Events : 570


      Number   Major   Minor   RaidDevice State
this     1       8       18        1      active sync   /dev/sdb2

   0     0       8        2        0      active sync   /dev/sda2
   1     1       8       18        1      active sync   /dev/sdb2
--

--- /proc/cmdline
root=/dev/md0 ro rootdelay=5

--- grub2:
insmod raid mdraid
set root=(md0)
	insmod raid mdraid
	set root=(md0)
	linux	/boot/vmlinuz-2.6.30-1-686 root=UUID=766297ed-997e-4b1e-9d6a-4d68a159301a ro  quiet
	insmod raid mdraid
	set root=(md0)
	linux	/boot/vmlinuz-2.6.30-1-686 root=UUID=766297ed-997e-4b1e-9d6a-4d68a159301a ro single 
	insmod raid mdraid
	set root=(md0)
	linux	/boot/vmlinuz-2.6.29-2-686 root=UUID=766297ed-997e-4b1e-9d6a-4d68a159301a ro  quiet
	insmod raid mdraid
	set root=(md0)
	linux	/boot/vmlinuz-2.6.29-2-686 root=UUID=766297ed-997e-4b1e-9d6a-4d68a159301a ro single 

--- grub legacy:
kernel		/boot/vmlinuz-2.6.30-1-686 root=/dev/md0 ro 
kernel		/boot/vmlinuz-2.6.30-1-686 root=/dev/md0 ro single
kernel		/boot/vmlinuz-2.6.29-2-686 root=/dev/md0 ro 
kernel		/boot/vmlinuz-2.6.29-2-686 root=/dev/md0 ro single

--- udev:
ii  udev           0.141-1        /dev/ and hotplug management daemon
46b1564ce5f5dedb5c7e2e6af67d48b7  /lib/udev/rules.d/64-md-raid.rules

--- /dev:
brw-rw---- 1 root disk 9, 0 2009-07-27 07:54 /dev/md0

/dev/disk/by-id:
total 0
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 ata-WDC_WD2500JS-00NCB1_WD-WCANK2817051 -> ../../sda
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 ata-WDC_WD2500JS-00NCB1_WD-WCANK2817051-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 ata-WDC_WD2500JS-00NCB1_WD-WCANK2817051-part2 -> ../../sda2
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 ata-WDC_WD2500KS-00MJB0_WD-WCANK1830655 -> ../../sdb
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 ata-WDC_WD2500KS-00MJB0_WD-WCANK1830655-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 ata-WDC_WD2500KS-00MJB0_WD-WCANK1830655-part2 -> ../../sdb2
lrwxrwxrwx 1 root root  9 2009-07-27 07:54 md-uuid-7e9d311e:35f7cf78:038d364c:261108ae -> ../../md0
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 scsi-SATA_WDC_WD2500JS-00_WD-WCANK2817051 -> ../../sda
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 scsi-SATA_WDC_WD2500JS-00_WD-WCANK2817051-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 scsi-SATA_WDC_WD2500JS-00_WD-WCANK2817051-part2 -> ../../sda2
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 scsi-SATA_WDC_WD2500KS-00_WD-WCANK1830655 -> ../../sdb
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 scsi-SATA_WDC_WD2500KS-00_WD-WCANK1830655-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 scsi-SATA_WDC_WD2500KS-00_WD-WCANK1830655-part2 -> ../../sdb2

/dev/disk/by-path:
total 0
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 pci-0000:00:0d.0-ide-0:0 -> ../../hda
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 pci-0000:00:0e.1-scsi-1:0:0:0 -> ../../sda
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 pci-0000:00:0e.1-scsi-1:0:0:0-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 pci-0000:00:0e.1-scsi-1:0:0:0-part2 -> ../../sda2
lrwxrwxrwx 1 root root  9 2009-07-27 07:51 pci-0000:00:0e.2-scsi-0:0:0:0 -> ../../sdb
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 pci-0000:00:0e.2-scsi-0:0:0:0-part1 -> ../../sdb1
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 pci-0000:00:0e.2-scsi-0:0:0:0-part2 -> ../../sdb2

/dev/disk/by-uuid:
total 0
lrwxrwxrwx 1 root root  9 2009-07-27 07:54 766297ed-997e-4b1e-9d6a-4d68a159301a -> ../../md0
lrwxrwxrwx 1 root root 10 2009-07-27 07:51 f102b3dd-59ed-4efe-aaf1-1c98e9d975c6 -> ../../sdb1

/dev/md:
total 0
lrwxrwxrwx 1 root root 6 2009-07-27 07:55 0 -> ../md0

Auto-generated on Mon, 27 Jul 2009 07:58:51 -0400
by mdadm bugscript 3.0-2

-- System Information:
Debian Release: squeeze/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.30-1-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages mdadm depends on:
ii  debconf                       1.5.27     Debian configuration management sy
ii  libc6                         2.9-22     GNU C Library: Shared libraries
ii  lsb-base                      3.2-23     Linux Standard Base 3.2 init scrip
ii  makedev                       2.3.1-88   creates device files in /dev
ii  udev                          0.141-1    /dev/ and hotplug management daemo

Versions of packages mdadm recommends:
ii  module-init-tools             3.9-2      tools for managing Linux kernel mo
ii  ssmtp [mail-transport-agent]  2.63-1     extremely simple MTA to get mail o

mdadm suggests no packages.

-- debconf information:
  mdadm/autostart: true
* mdadm/mail_to: root
  mdadm/initrdstart_msg_errmd:
* mdadm/initrdstart: all
  mdadm/initrdstart_msg_errconf:
  mdadm/initrdstart_notinconf: false
  mdadm/initrdstart_msg_errexist:
  mdadm/initrdstart_msg_intro:
* mdadm/autocheck: true
  mdadm/initrdstart_msg_errblock:
* mdadm/start_daemon: true





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