Bug#496334: mdadm: --assemble -f also fails in a raid5 setup

Sun Aug 31 02:20:10 UTC 2008

Package: mdadm
Version: 2.6.7-3
Followup-For: Bug #496334

This also happens for a RAID 5 setup. Specifically,
I was working on a degraded RAID5 (four out of five
disks present) when a bus error or similar stopped
md_mod from talking to one of the disks, which was
then marked faulty.

After a reboot I tried to tell mdadm that all was
well again, but it kept segfaulting.
Downgrading to lenny's mdadm (2.5.6-9) allowed me to
re-sync the metadata and use the array again normally.

No filesystems were harmed in the production of this
bugreport.

FWIW, the array has version 00.90 metadata.

Ciao,
  Philipp

-- Package-specific info:
--- mount output
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)
procbususb on /proc/bus/usb type usbfs (rw)
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)
rootfs on / type rootfs (rw)
/dev/md8 on /boot type ext2 (rw)
/dev/md1 on /mnt type xfs (ro)

--- 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/md1 level=raid5 num-devices=5 UUID=XXXXXXXX:XXXXXXXX:XXXXXXXX:XXXXXXXX

# This file was auto-generated on Sun, 31 Aug 2008 03:08:52 +0200
# by mkconf $Id$

--- /proc/mdstat:
Personalities : [raid6] [raid5] [raid4] [raid1] 
md8 : active raid1 hde1[0]
      521984 blocks [6/1] [U_____]

md1 : active raid5 hdk1[0] hda1[3] hdg1[2] hdi1[1]
      312463872 blocks level 5, 64k chunk, algorithm 2 [5/4] [UUUU_]

unused devices: <none>

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

   3     0   78150744 hda
   3     1   78148161 hda1
  33     0   80043264 hde
  33     1     522081 hde1
  33     4          1 hde4
  33     5    1004031 hde5
  33     6    1004031 hde6
  34     0   80418240 hdg
  34     1   80418208 hdg1
  56     0   78150744 hdi
  56     1   78148161 hdi1
  57     0   78184008 hdk
  57     1   78183976 hdk1
   9     1  312463872 md1
   9     8     521984 md8

--- initrd.img-2.6.24-1-486:
31716 blocks
etc/mdadm
etc/mdadm/mdadm.conf
sbin/mdadm
lib/modules/2.6.24-1-486/kernel/drivers/md/linear.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/md-mod.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/raid10.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/dm-mod.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/raid1.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/multipath.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/dm-snapshot.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/dm-crypt.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/raid456.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/dm-mirror.ko
lib/modules/2.6.24-1-486/kernel/drivers/md/raid0.ko
scripts/local-top/mdadm

--- /proc/modules:
dm_crypt 13188 0 - Live 0xe0a45000
dm_mirror 20480 0 - Live 0xe0941000
dm_snapshot 16800 0 - Live 0xe0848000
dm_mod 54596 3 dm_crypt,dm_mirror,dm_snapshot, Live 0xe0911000
raid1 21504 1 - Live 0xe090a000
raid456 119824 1 - Live 0xe0922000
md_mod 71956 4 raid1,raid456, Live 0xe08a5000
async_xor 2816 1 raid456, Live 0xe0815000
async_memcpy 1920 1 raid456, Live 0xe0810000
async_tx 2560 1 raid456, Live 0xe080e000
xor 14344 2 raid456,async_xor, Live 0xe08a0000

--- volume detail:

--- /proc/cmdline
root=UUID=402fb363-be9c-4cd5-9d77-60d84b5f4770 ro 

--- grub:
kernel		/vmlinuz-2.6.24-1-486 root=UUID=402fb363-be9c-4cd5-9d77-60d84b5f4770 ro 
kernel		/vmlinuz-2.6.24-1-486 root=UUID=402fb363-be9c-4cd5-9d77-60d84b5f4770 ro single

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (500, 'testing'), (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 2.6.24-1-486
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash

Versions of packages mdadm depends on:
ii  debconf                       1.5.22     Debian configuration management sy
ii  libc6                         2.7-13     GNU C Library: Shared libraries
ii  lsb-base                      3.2-19     Linux Standard Base 3.2 init scrip
ii  makedev                       2.3.1-88   creates device files in /dev
ii  udev                          0.125-5    /dev/ and hotplug management daemo

Versions of packages mdadm recommends:
ii  exim4-daemon-light [mail-tran 4.69-6     lightweight Exim MTA (v4) daemon
ii  module-init-tools             3.4-1      tools for managing Linux kernel mo

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