md driver doesn't notice disk going out

From: Michael S. Fischer (michael@auctionwatch.com)
Date: Tue Apr 03 2001 - 19:09:13 EST


Hello,

We're testing lvm over md (RAID 1) for a database application. Part of our
tests include simulating failure. So, we pulled the power on one of the
drives, and the kernel reported...

hdd: status error: status=0x00 { }
hdd: drive not ready for command
...
ide1: reset timed-out, status=0x80
hdd: lost interrupt
hdd: lost interrupt
hdd: lost interrupt
...

However, /proc/mdstat still reports:

Personalities : [linear] [raid0] [raid1] [raid5]
read_ahead 1024 sectors
md1 : active raid1 hdd[1] hdb[0]
      19925760 blocks [2/2] [UU]
      
md0 : active raid1 hdc[1] hda[0]
      19925760 blocks [2/2] [UU]

It appears the md driver just didn't bother to notice -- and now all writes
to the filesystem are blocked.

In case it matters, here's our lvm config:

--- Volume group ---
VG Name data0_vg
VG Access read/write
VG Status available/resizable
VG # 0
MAX LV 256
Cur LV 1
Open LV 1
MAX LV Size 255.99 GB
Max PV 256
Cur PV 2
Act PV 2
VG Size 38 GB
PE Size 4 MB
Total PE 9728
Alloc PE / Size 7680 / 30 GB
Free PE / Size 2048 / 8 GB
VG UUID 6XH7Nq-JL9u-cbjw-rUoP-Kx9o-hlZN-LPhdmj

--- Logical volume ---
LV Name /dev/data0_vg/data0_lv
VG Name data0_vg
LV Write Access read/write
LV Status available
LV # 1
# open 1
LV Size 30 GB
Current LE 7680
Allocated LE 7680
Stripes 2
Stripe size (KByte) 16
Allocation next free
Read ahead sectors 120
Block device 58:0

--- Physical volumes ---
PV Name (#) /dev/md0 (1)
PV Status available / allocatable
Total PE / Free PE 4864 / 1024

PV Name (#) /dev/md1 (2)
PV Status available / allocatable
Total PE / Free PE 4864 / 1024

Please CC: me on replies. Thanks.

--
Michael S. Fischer / michael at auctionwatch.com /
http://www.auctionwatch.com
Systems Engineer, AuctionWatch.com Inc. / Phone: +1 650 808 5842  
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This archive was generated by hypermail 2b29 : Sat Apr 07 2001 - 21:00:13 EST