I've set up at least a dozen RAIDs in Linux, with a variety of weird
configurations, so I feel comfortable commenting on this.
Don't bother with fake RAID (the module is dmraid, IIRC) if you're not
dual-booting. Software RAID is reasonably fast in Linux, especially if
you're not using a level that involves parity checks, like RAID 5 -
this tends to be the performance killer in my experience.
I know this isn't going to be well-received advice by some folks, but
I'd recommend a switch to RHEL, CentOS, or Fedora. I know for a fact
that all of those have excellent support for RAID (and LVM) in their
installers (both GUI and text), making setup a snap.
No idea about swap performance with RAID 0 versus two separate disks -
but I doubt it matters, since we're still dealing with orders of
magnitude difference between your hard drive and RAM.
If you're planning on running RAID 0, be sure you understand the
inherent risks involved. And back up regularly! :)
-DMZ
Quoting Nick Cummings <[EMAIL PROTECTED]>:
I was recently given a new mobo with an nForce chipset that claimed to
have a RAID controller and two identical SATA drives with the idea that
I could use it for a RAID0. Before being given this setup, I hadn't
really given a lot of thought to running a RAID, but I'm thinking its
at least now worth a try.
After doing a bit of reading, it appears that the "RAID controller" on
the mobo is actually a so-called "fake RAID" that needs a driver which
actually implements much of the RAID functionality. My options then
were to try to find a working driver for Linux or to use a straight
software RAID. Anyone have any idea how the two of these compare?
I read several claims that the software RAID in Linux is as fast or
faster than most of these fake RAIDs, but I remain a bit skeptical.
Anyone know about that? Stuff I read seemed to suggest that one
downside of the fake RAID is that it could only be read by that chipset
(or a similar one) while the software RAID could be read by any system
with Linux (and appropriate modules). I know an upside of fake RAID is
that if you're dual booting it can be read by Windows, but I'm not dual
booting, so this is a non-issue.
I initially chose to go with the software RAID, thinking it would be
easier and more compatible, but I'm having a hell of a time getting
Ubuntu to setup the RAID and install. Right now my system won't boot
properly (seems it does not like having / on a RAID). So I have an
opportunity to reconsider my decision.
Another related question is whether anyone know how the performance
compares of having two ordinary swap partitions set to the same
priority versus having a RAID0 swap partition using the two disk? Is
one significantly better than the other? Is neither all that useful?
Finally, since Ubuntu's support for setting up a RAID at install seems
pretty bad, can anyone suggest distributions in which this goes more
smoothly? All things being equal, I probably prefer debian-based
distros, since that's what I'm familiar with.
Thanks,
Nick
