Multiple choices for RAID-0, best performance?
Brad Knowles
brad.knowles at skynet.be
Fri Jun 25 02:26:50 PDT 2004
At 11:49 PM -0700 2004-06-24, David O'Brien wrote:
> Why "maybe ccd"??
> It works fine. I've been using ccd(4) for the past 4 years for all my
> FreeBSD development drive space.
I said that (at the time) because I was not 100% certain of the
implementation of ccd, and wasn't convinced that it was a true
striping solution as opposed to a simple concatenation (which would
get you the same disk storage space, but not the performance).
I know that vinum used to be the best thing around for striping
and mirroring (witness my page at
<http://www.shub-internet.org/brad/FreeBSD/>, and the fairly highly
rated USENET news peering server I built in the Joe Greco style), but
I always had problems with the RAID-5 stuff, and I had problems with
interactions between vinum and softupdates.
More recently, vinum seems to have suffered from bitrot (well, it
didn't keep up with all the other changes going on), and other people
mentioned that they weren't using it anymore and had gone back to
using ccd (especially Joe).
I'm hoping that the new geom_vinum and geom_stripe stuff will
give us a better and more robust solution than we previously had on
the software side, and I'm hoping that Søren (and others) can
continue to work on the hardware side through improvements to the
ataraid drivers, etc....
But in the meanwhile, there's a lot of stuff that used to work, a
lot of stuff that is under development, and it's not exactly clear to
me just what is really stable and usable at this current point in
time.
--
Brad Knowles, <brad.knowles at skynet.be>
"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
-Benjamin Franklin, Historical Review of Pennsylvania.
SAGE member since 1995. See <http://www.sage.org/> for more info.
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