> If these are SCSI disks, removing power can cause a MULTITUDE of problems
> you won't see if the SCSI connection to a drive fails. Unless the drives
> and controller aren't the original SCSI 1 8 bit bus, the termination has
> power supplied by the drive.
On many drives, you can choose via Jumper where termpower comes from.
A common advice is to use termpower from the scsi bus (which is powered by
the host adaptor).
> Removing the power kills the termination and
> will lleave the bus in an undetermined state, with an unknown load on the
> bus as well.
Really ??? I think I have read that power-off SCSI devices shall be passive
to the bus. If you think of external SCSI devices, they are switched on/off
quite often during normal operation.
> restore the data... that is unless the raid was active when you unplugged
> the drive, as SCSI drives have a large RAM cache that probably got
> corrupted, and the data was never written to the 2 drives.
The data on the drive that was unplugged shouldn't matter as the intention
was to simulate a FAILURE of THAT drive.
As I wrote in last mail, I also tried this procedure some times.
Mostly it worked, only in some cases I had a system continously resetting the
scsi bus - maybe that has happened to him (system is quite unresponsive to
user during that).
Thomas
