On Fri, Jun 18, 2010 at 04:52:02AM -0400, Curtis E. Combs Jr. wrote:
> I am new to zfs, so I am still learning. I'm using zpool iostat to
> measure performance. Would you say that smaller raidz2 sets would give
> me more reliable and better performance? I'm willing to give it a
Yes, more smaller raid-sets will give you better performance,
since zfs distributes (stripes) data on all of them.
What's your IO pattern? random writes? sequential writes?
Basicly if you have 2x 11-disk raidz2 sets you'll be limited to around
performance of 2 disks, in the worst case of small random IO.
(the parity needs to be written and that limits the performance of raidz/z2/z3
to the performance of single disk).
This is not really zfs specific at all, it's the same with any raid
> On Fri, Jun 18, 2010 at 4:42 AM, Pasi Kärkkäinen <pasik@xxxxxx> wrote:
> > On Fri, Jun 18, 2010 at 01:26:11AM -0700, artiepen wrote:
> >> Well, I've searched my brains out and I can't seem to find a reason for
> >> this.
> >> I'm getting bad to medium performance with my new test storage device.
> >> I've got 24 1.5T disks with 2 SSDs configured as a zil log device. I'm
> >> using the Areca raid controller, the driver being arcmsr. Quad core AMD
> >> with 16 gig of RAM OpenSolaris upgraded to snv_134.
> >> The zpool has 2 11-disk raidz2's and I'm getting anywhere between 1MB/sec
> >> to 40MB/sec with zpool iostat. On average, though it's more like 5MB/sec
> >> if I watch while I'm actively doing some r/w. I know that I should be
> >> getting better performance.
> > How are you measuring the performance?
> > Do you understand raidz2 with that big amount of disks in it will give you
> > really poor random write performance?
> > -- Pasi
> >> I'm new to OpenSolaris, but I've been using *nix systems for a long time,
> >> so if there's any more information that I can provide, please let me know.
> >> Am I doing anything wrong with this configuration? Thanks in advance.
> >> --
> >> This message posted from opensolaris.org
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> Curtis E. Combs Jr.
> System Administrator Associate
> University of Georgia
> High Performance Computing Center
> Office: (706) 542-0186
> Cell: (706) 206-7289
> Gmail Chat: psynophile@xxxxxxxxx
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