Re: adding a RAID component

["Steven M. Bellovin" <smb%cs.columbia.edu@localhost>]

On Tue, 18 Aug 2009 23:01:43 +0200 (CEST)
Havard Eidnes <he%NetBSD.org@localhost> wrote:

> > Short form: I'm trying to add a second drive for RAID mirroring --
> > how do I do it?
> >
> > Full story: I built a 5.0 system (per the instructions on the Wiki)
> > using just one drive of a RAID1 set.  I'd have added both
> > components at that time, but the machine I was working on didn't
> > have a spare SATA connector...
> >
> > Anyway -- both disks are now in the proper machine.  I'm running
> > from raid0 on wd0e.  How do I persuade it to start using wd1 as the
> > mirror drive?
> 
> I think the operation you want is "add a new hot spare and start
> a raid rebuild onto it", provided by the following sequence:
> 
> raidctl -a /dev/wd1e raid0
> raidctl -F component1 raid0
> 
> Before that you of course need to have marked wd1e as type RAID
> in the disklabel and it needs to be the exact same size as wd0e.
> 
Ah -- I said "/dev/wd1e" (and other assorted variants of that drive --
instead of "component1" in the second command.  It is *not* obvious
from the early parts of the man page that the correct value is even
legal, let alone correct -- though now that I know the right answer, I
can read a third of the way down and see that.

Thanks -- 'raidctl -S' tells me that in ~7 hours, I'll have a spare
drive.  I hope so -- I'm not sure how long Murphy's vacation will last.


                --Steve Bellovin, http://www.cs.columbia.edu/~smb