Hi,
I am running a server using debian sarge. Linux kernel 2.6.8, mdadm was
1.8.1. I described the onset of my disaster in an earlier exchange with David
Greaves on this list.
My server had 1 sata system drive /dev/sda and 5 ide data drives configured
as 3 different raid1's.
I had
/dev/md0 /dev/hda1 /dev/hdg1
/dev/md1 /dev/hdc1 /dev/hdi1
/dev/md2 /dev/hde1 missing
Then I had a catastrophic loss of /dev/md0.
What happened was that hda1 died and simultaneously hdg1
began to have nonstop write errors.
I then tried to rescue the data on /dev/hdg1. I failed drive /dev/hdi1 from
/dev/md1 and added it to /dev/md0.
Unfortunately, the rebuilding of /dev/md0 did not proceed, despite my allowing
a day for it to take place.
(Incidentally the copious write error messages from /dev/hdg1 were written to
syslog which filled the /var directory. This lead to many difficulties in my
administering the system, affecting a Postgresql database I had on the
system ... another story)
I then removed the two hard drives (dead) hda1 and (dying) hdg1. I replaced
them with 2 new hard drives.
Here was my
# /etc/fstab: static file system information.
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
/dev/sda2 / ext3 defaults,errors=remount-ro 0 1
/dev/sda1 /boot ext3 defaults 0 2
/dev/sda3 /home ext3 defaults 0 2
/dev/sda8 /mirror ext3 defaults 0 2
/dev/sda7 /tmp ext3 defaults 0 2
/dev/sda6 /var ext3 defaults 0 2
/dev/sda5 none swap sw 0 0
/dev/hda /media/cdrom0 iso9660 ro,user,noauto 0 0
/dev/md0 /home/big0 ext3 noauto 0 0
/dev/md1 /home/big1 ext3 defaults 0 2
/dev/md2 /home/big2 ext3 defaults 0 2
Here was my /etc/mdadm/mdadm.conf
DEVICE /dev/hda1 /dev/hdc1 /dev/hde1 /dev/hdg1 /dev/hdi1
ARRAY /dev/md2 level=raid1 num-devices=2
UUID=6b8b4567:327b23c6:643c9869:6633483
devices=/dev/hde1
ARRAY /dev/md1 level=raid1 num-devices=2 spares=1
UUID=6b8b4567:327b23c6:643c983
devices=/dev/hdc1,/dev/hdi1
ARRAY /dev/md0 level=raid1 num-devices=2 spares=1
UUID=6b8b4567:327b23c6:643c983
devices=/dev/hda1,/dev/hdg1
After I replaced the two new hard drives, I found that the machine would not
reboot unless I commented out the /dev/md0 and /dev/md1 in the /etc/fstab.
For good measure I also commented out /dev/md2 as well.
Now I can reboot and I have.
A2:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 9.2G 2.8G 6.0G 32% /
tmpfs 443M 0 443M 0% /dev/shm
/dev/sda1 89M 11M 74M 13% /boot
/dev/sda3 7.4G 365M 6.7G 6% /home
/dev/sda8 11G 8.9G 1.1G 90% /mirror
/dev/sda7 449M 8.1M 417M 2% /tmp
/dev/sda6 7.4G 951M 6.1G 14% /var
Now comes the weird part. I expected that when I did cat /proc/mdstat
I would see 2 working /dev/md1 and /dev/md2. Because both /dev/hdc1
and /dev/e1 are still ok.
In fact what I see is
A2:~# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 hde1[1]
244195904 blocks [2/1] [_U]
unused devices: <none>
Question 1) What happened to /dev/md1 and /dev/hdc1?
I then followed the advice of
David Greaves , and I upgraded to mdadm-1.9.0 as 1.8.1 is experimental.
I then did
mdadm --examine /dev/hdc1
A2:~# mdadm --examine /dev/hdc1
/dev/hdc1:
Magic : a92b4efc
Version : 00.90.00
UUID : 6b8b4567:327b23c6:643c9869:66334873
Creation Time : Wed Jan 12 14:19:46 2005
Raid Level : raid1
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Update Time : Sun Mar 13 10:19:59 2005
State : clean
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
Checksum : a4499264 - correct
Events : 0.514
Number Major Minor RaidDevice State
this 1 22 1 1 active sync /dev/hdc1
0 0 0 0 0 removed
1 1 22 1 1 active sync /dev/hdc1
2:~# mdadm --examine /dev/hdi1
/dev/hdi1:
Magic : a92b4efc
Version : 00.90.00
UUID : 6b8b4567:327b23c6:643c9869:66334873
Creation Time : Wed Jan 12 14:19:21 2005
Raid Level : raid1
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Update Time : Fri Mar 11 11:40:23 2005
State : clean
Active Devices : 1
Working Devices : 2
Failed Devices : 1
Spare Devices : 1
Checksum : a4517972 - correct
Events : 0.343412
Number Major Minor RaidDevice State
this 2 56 1 2 spare /dev/hdi1
0 0 34 1 0 active sync /dev/hdg1
1 1 0 0 1 faulty removed
2 2 56 1 2 spare /dev/hdi
Then I did
fdisk -l
A2:~# fdisk -l
Disk /dev/sda: 40.0 GB, 40020664320 bytes
255 heads, 63 sectors/track, 4865 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 1 12 96358+ 83 Linux
/dev/sda2 13 1228 9767520 83 Linux
/dev/sda3 1229 2201 7815622+ 83 Linux
/dev/sda4 2202 4865 21398580 f W95 Ext'd (LBA)
/dev/sda5 2202 2444 1951866 82 Linux swap
/dev/sda6 2445 3417 7815591 83 Linux
/dev/sda7 3418 3478 489951 83 Linux
/dev/sda8 3479 4865 11141046 83 Linux
Disk /dev/hde: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hde1 1 30401 244196001 fd Linux raid autodetect
Disk /dev/hdg: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/hdg doesn't contain a valid partition table
Disk /dev/hdi: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hdi1 1 30401 244196001 fd Linux raid autodetect
Disk /dev/hda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/hda doesn't contain a valid partition table
Disk /dev/hdc: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hdc1 1 30401 244196001 fd Linux raid autodetect
Any Ideas on why I don't have an active /dev/md1??????
What steps do I take to preserve the data on /dev/md1? I know I can now
rebuild /dev/md0 the usual way.
Does the fact that the system booted with the /etc/mdadm/mdadm.conf that was
"incorrect" because it mentioned that /dev/hdi1 was a partner with /dev/hdc1
have anything to do with this????
Thanks,
Mitchell Laks
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