On Fri, 24 Sep 1999, Brian Murphy wrote:
> Hi again,
> well today I repeated the test pulling out the disk and waiting a
> longer time - with
> no success. I did a raidhotremove on the failed partitions and then
> added them back
> with raidhotadd, a cat of /proc/mdstat revealed a quickly increasing
> finish time to
> recovery of the mirror
>
> md3 : active raid1 sdb8[2] sda8[0] 6707008 blocks [2/1] [U_] recovery=0%
> finish=119606.5min (and rising)
I have fiddled with this hotswapping thing also. My experience
was that after removing adding the performance degraded to
like 1/10th of the original. I figured out that it might have
to do something about scsi defaulting back to async transfer
mode after adding.
Also noticed that when i really changed the physical disk
to the scsi bus, few times everything went find and i was
able to start recovery process but like 40% of the cases
my kernel panicked when the raid accessed first time the
new replaced disk. Tho the bug might still sit between
keyboard and chair. So what i am asking is that
what is the _correct_ procedure to add a scsi device on
the fly to to the bus?
I did something like this: (if i remember correctly)
raidsetfaulty /dev/md0 /dev/sda1
echo "scsi remove-single-device 0 0 0 0" >/proc/scsi/scsi
<this point i made the physical change operation of disk>
echo "scsi add-single-device 0 0 0 0" >/proc/scsi/scsi
<at this point the kernel correctly did found the addded device>
raidhotadd /dev/md0 /dev/sda1
<sometimes got panic in here>
Few times the recovery process started, few times the kernel
just paniced. Can someone straight ahead say what i am
doing wrong ?
-- Mika
