On Thu, 27 Jul 2000, Art wrote:
> After pulling out one disk (system off line), it came back on line with the
> data intact... It started automatically the reconfiguration using the spare
> disk.
> The funny thing was, after reinserting the original disk it did not
> reconfigure it automatially. I had to raidhotadd the disk. Then it started
> reconfiguring it.
That's expected behaviour.
> I would like to be able to stop my raid array and switch off the power of
> this box (not the computer). If I switch the array off and on, the scsi
> disks do not spindle up. So I have to reboot the machine (scsi card spindles
> them up). This is a bit awkward.
Check out /usr/src/linux/drivers/scsi/scsi.c. You need to do some magic
with 'remove-single-device' and then, after restarting the disks,
'add-single-device'. If you turn your disk off without first removing it
from /proc/scsi/scsi, the controller seems to get confused...
> Can the raid-software also control the above mentioned leds?
AFAIK, no.
> What is translucent mode?
No idea, it's just not supposed to be used... :)
> Which drive is my hotspare if I issue `cat /proc/mdstat` ?
md0 : active raid5 sdd2[3] sdc2[2] sdb2[1] sda2[0] 17333888 blocks level
5, 32k chunk, algorithm 2 [3/3] [UUU]
I suppose active RAID drives are numbered from 0, meaning that 0, 1 and 2
are active (in a 3+1 RAID5 array). So number sdd2[3] is the spare drive.
> Is it possible to modify the raidstart/stop code so that it uses scsi
> commands to start/stop the disks (in a running machine)?
This is trivial as software raid is not limited to SCSI disks only, so
that would involve quite a lot of sanity checking...
However, it's pretty easy to write a couple of scripts doing just that.
D.
