Subject: Is it possible to set up a RAID on Firewire?
To: None <>
From: John F. Woods <>
List: current-users
Date: 10/23/2004 14:49:02
Actually, I gather from searching through the mail archives that the answer
is "no", but I'm wondering how many reasons there are that one can't do that
and whether any or all of reasons might be fixed soon.

I assume the first stumbling block is that the firewire disk code currently
just doesn't work.  I see that someone has ported FreeBSD's sbp code and
that it supposedly works; is that going to be integrated anytime soon, or
is the existing framework going to be fixed?

Even if that worked, would the RAIDframe driver work right with Firewire
drives?  I see that RAIDframe names constituent drives with traditional
device pathnames, and the last time I paid much attention to NetBSD's
strategy for naming dynamically attached devices (like USB devices),
the association with a drive and its pathname was pretty much just luck
of the draw, or has some scheme been implemented for persistently naming
removable drives?

I'm currently runnning 1.6F on an old Pentium 2, and I'm trying to figure
out what kind of upgrades I should be planning for[1].  The origin of the
specific question above:  In addition to my home server running NetBSD,
I also have a bunch of Macs running Mac OS X.  I back up the Macs using
Retrospect running on one machine, which has a couple of 200G Firewire disks
for exactly that purpose[2].  I'm running out of space for backups, so it's
probably time to add another disk, and it occurs to me that if I added two
more to the existing two, I could set up a RAID-4 or RAID-5 set and have
some extra security for my backups.  Unfortunately, Mac OS X's built-in
RAID software only does RAID-0 and RAID-1, so two more drives can get me
more storage or more redundancy, but not both.  Retrospect can back up to
an FTP server, so the NetBSD box could easily host the RAID set -- if it
had enough places to put enough disks...

John Woods

[1] After all, I've got two outstanding PRs that I need to verify so
they can be closed...

[2] Oh, for the days when tape was fast enough, reliable enough, large
enough, and cheap enough to be used as a backup medium for contemporary
disks.  Shockingly, none of those seem to be really true nowadays..