On Thu, 2002-07-18 at 16:51, Ben Gollmer wrote:
> I'm going to stick with the Promise ATA-133 controllers, as they are only $30
> at www.newegg.com. Also I am using software RAID, the 3ware controllers that
> I looked at were hardware RAID only and too expensive - I'd rather have more
> storage space.
Cool! I didn't know they were so cheap (inexpensive).
> Quick question for anyone with Linux software RAID experience: our RAID 0
> be composed of two RAID 1s, md0 and md1. if we decide we need more storage,
> is it easy to create another RAID 1 (md2) and add it to the stripe set? Or
> would that require something like LVM (or even a re-format)?
Well, actually, there *is* a utility that can convert between raid
levels and # of disks. For example, you can convert a 3 disk raid5 to a
4 disk raid5. You can also do what you want to in your question. It's
called "raidreconf", and is now included with the standard raid-tools
package. The RAID must be offline, and the tool runs in user-space. It
can run for long periods, and you should make a backup before hand, just
in case. If it runs to completion (barring a power failure, for
example), then it'll save you at least the copy in. See
http://unthought.net/raidreconf/ for more info and warnings.
In the spirit of full disclosure, I did write the RAID5 portion of the
tool. Jakob Ostergaard did the real work.
Hope this helps!
kernel, n.: A part of an operating system that preserves the
medieval traditions of sorcery and black art.