Recommended RAID controller

[Kenneth D. Merry]

On Tue, Jun 29, 2004 at 19:18:30 -0500, Bob Willcox wrote:
> On Tue, Jun 29, 2004 at 04:52:01PM -0700, randall ehren wrote:
> > > > on a side note, does anyone know if it's possible to initiate a RAID
> > rebuild
> > > > using these utilities? they seem to only allow the viewing or status,
> > but
> > > > not initiate any changes...
> > >
> > > I thougth that the rebuild would be initiated automatically when you
> > > plug in the new drive. Is that not so?
> > 
> > nope. put a new drive in, can't reboot the machine until this weekend, been
> > like this for about 36 hours now...
> 
> Bummer. Seems like that ought to be automatic.

Well, if you're writing the RAID controller firmware, you'll often want
some user intervention prior to treating a newly inserted drive as a spare.

What if the user accidentally plugged the drive into the wrong SCSI (or
SATA or FC or ATA) bus?

What if the user just wanted to treat the new drive as a volume, and put it
on the controller so he could access it?

What if you have 2 (or more) failed arrays, how do you decide which array
gets the spare?

You get the idea.  You want to ask the user before potentially overwriting
his data.  There are probably some RAID boxes that do treat newly inserted
drives as spares immediately, but you pretty much need some sort of
standing policy on what to do with a "foreign" drive in that case.

Ken
-- 
Kenneth Merry
ken at kdm.org