Bug#287415: mdadm: degraded md devices not assembled on boot

Sun Jul 23 21:02:35 UTC 2006

Package: mdadm
Version: 2.5.2-7
Followup-For: Bug #287415

I'm pretty new to RAID, so please be patient with me...

I first configured mdadm to assemble all the arrays in initramfs; as I
noticed a bunch of output about wrong uuids at boot, I firstly thought
that I probably made some mistake when creating the arrays.

After some investigation - I'm a novice, remember! - I found that uuids
were OK, superblocks also and so on: those error messages were printed
only if assemblation were made early in initramfs, if I assembled the
arrays when the box was started no errors messages were shown and
everything ran fine.

As I have to provide a clean and working server I didn't liked those
errors. I must necessarily use sid as kernels before 2.6.17 don't play
well with the hardware I'm using. So I tried to dpkg-reconfigure -plow
mdadm and I specified to assemble in initramfs phase only the root
device (md0): this eliminated all the "wrong uuid" messages.

As usual, I started playing with that brand new beast to verify that
everything was working as expected: one test I made was to shut off the
server, remove an entire drive, i.e. sdb, and reboot.

The boot process stopped when checkfs.sh attempted to check the md[1245]
filesystems: "no such device". Also typing CONTROL+D to continue the
boot process showed that mdadm could not assemble the devices. What
surprised me was that I could assemble those devices manually by running
i.e. mdadm -Av /dev/md2.

Please note that, despite the "wrong uuid" messages, the degraded
devices _can_ be assembled correctly in initramfs.

Did I miss something?

Thanks

Mau

-- Package-specific info:
--- mount output
/dev/md0 on / type ext3 (rw,noatime,errors=remount-ro)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
usbfs on /proc/bus/usb type usbfs (rw)
tmpfs on /dev/shm type tmpfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/md2 on /tmp type ext3 (rw,noatime,errors=remount-ro)
/dev/md4 on /var type ext3 (rw,noatime,errors=remount-ro)
/dev/md5 on /home type ext3 (rw,noatime,errors=remount-ro)
tmpfs on /dev type tmpfs (rw,size=10M,mode=0755)

--- mdadm.conf
DEVICE /dev/sda* /dev/sdb*
CREATE owner=root group=disk mode=0660 auto=yes metadata=1
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=878e305f:04aa9637:8dbfd7d0:80f8e60c
ARRAY /dev/md1 level=raid1 num-devices=2 UUID=fffd69a2:70d3c6ee:3720604f:a9d4b932
ARRAY /dev/md2 level=raid1 num-devices=2 UUID=4a4402b6:b24bfbb8:7a51b030:daaeca32
ARRAY /dev/md4 level=raid1 num-devices=2 UUID=ac0f413d:52ebe0bb:066fbc91:23396cc5
ARRAY /dev/md5 level=raid1 num-devices=2 UUID=c9435bdb:f3ad470a:f521b3a6:2850eb25
MAILADDR root

--- /proc/mdstat:
Personalities : [raid1] 
md5 : active raid1 sda6[0] sdb6[1]
      40073984 blocks [2/2] [UU]

md4 : active raid1 sda5[0] sdb5[1]
      31463168 blocks [2/2] [UU]

md2 : active raid1 sda3[0] sdb3[1]
      1052160 blocks [2/2] [UU]

md1 : active raid1 sda2[0] sdb2[1]
      1574272 blocks [2/2] [UU]

md0 : active raid1 sdb1[1] sda1[0]
      3984000 blocks [2/2] [UU]

unused devices: <none>

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

   8     0   78150744 sda
   8     1    3984088 sda1
   8     2    1574370 sda2
   8     3    1052257 sda3
   8     4          1 sda4
   8     5   31463271 sda5
   8     6   40074111 sda6
   8    16   78150744 sdb
   8    17    3984088 sdb1
   8    18    1574370 sdb2
   8    19    1052257 sdb3
   8    20          1 sdb4
   8    21   31463271 sdb5
   8    22   40074111 sdb6
   9     0    3984000 md0
   9     1    1574272 md1
   9     2    1052160 md2
   9     4   31463168 md4
   9     5   40073984 md5

--- initrd.img-2.6.17-1-686:
20593 blocks
sbin/mdadm
lib/modules/2.6.17-1-686/kernel/drivers/md/raid6.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/linear.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/xor.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/raid10.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/md-mod.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/multipath.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/raid5.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/raid0.ko
lib/modules/2.6.17-1-686/kernel/drivers/md/raid1.ko
conf/mdadm.conf
scripts/local-top/mdadm

--- /proc/modules:
dm_mod 49976 0 - Live 0xf0e49000
raid1 20480 5 - Live 0xf0820000
md_mod 68884 6 raid1, Live 0xf082f000

--- volume detail:

-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.17-1-686
Locale: LANG=it_IT at euro, LC_CTYPE=it_IT at euro (charmap=ISO-8859-15)

Versions of packages mdadm depends on:
ii  debconf [debconf-2.0]         1.5.2      Debian configuration management sy
ii  libc6                         2.3.6-15   GNU C Library: Shared libraries
ii  lsb-base                      3.1-10     Linux Standard Base 3.1 init scrip
ii  makedev                       2.3.1-82   creates device files in /dev

Versions of packages mdadm recommends:
ii  exim4-daemon-light [mail-tran 4.62-2     lightweight exim MTA (v4) daemon

-- debconf information:
* mdadm/autostart: true
* mdadm/mail_to: root
* mdadm/initrdstart: all
* mdadm/autocheck: true
* mdadm/warning:
* mdadm/start_daemon: true