"Brandon D. Valentine" writes:
> On Tue, 23 Oct 2001, Jukka Marin wrote:
> 
> >On Tue, Oct 23, 2001 at 01:47:34PM -0500, Tom Uban wrote:
> >> Is there any sort of software support for using a second (identical)
> >> drive for redundancy in case of primary disk failure?
> >
> >Does 'man raid' help any?
> 
> It helps him insofar as realizing that what he wants is RAID1 to mirror
> his system disk.  However, although he can boot off of a RAID1 in the
> latest version of NetBSD, it still doesn't provide any redundancy in
> case of primary disk failure.  If that first disk fails, chances are it
> has his requisite non-mirrored boot partition on it containing the
> kernel and/or boot loader.  This is something which software RAID cannot
> get around; a BIOS or PROM is going to want to load the
> kernel/bootloader off of a single disk, it knows nothing of software
> RAID.  If he wants his system to recover from a disk failure gracefully
> he should look at hardware raid controllers, it's the only option.

Umm... no.  Just make sure the other disks are bootable as well. 
(i.e. duplicate the non-mirrored 'stuff needed to boot' onto the 2nd disk.)
I havn't tried this on sparc, but I have used dd to do it on i386, and it 
worked quite well.  (mark the normal boot disk as failed, hot pull it out.. 
reboot. watch the machine boot from the 2nd drive.  hot add 1st drive, 
re-sync mirrors, continue happily.)

Later...

Greg Oster