Configure the amanda workspace as a UFS stripe.  The features of
ZFS are not entirely 'free'.  My benchmarks indicate that a UFS
stripe will out-perform a ZFS stripe by 20% or more.

On Tue, Sep 15, 2009 at 09:56:46AM -0400, Brian Cuttler wrote:
> 
> I am running amanda 1.6.1.p1 on Solaris 10/x86.
> The only client is the server itself.
> 
> There are 17 DLEs in amanda's disklist, while only 15 mount points
> are listed, I'd divided /stations (it needs to be divided differently
> but that is a negligable issue).
> 
> I am running zfs-snapshots with server estimates excepting the
> since UFS file system /.
> 
> From the very bottom of the list you can see that I have allocated
> another zfs array for use as amanda work, it holds 4 Terra which
> should be enough to dump all of the other paritions concurrently,
> we aren't doing so, but holding space is not our performance block.
> 
> Our performance block, per system monitoring is the throughput
> to the amanda work area. We had it configured as raid, its now
> a stripe, with no better performance per our test suite.
> 
> What if any switches can I tune (either within amanda or in ZFS)
> to get better I/O across the work area drives ? The array consists
> of 8 750Gig spindles a an ultra 320 bus.
> 
> We output to an SL24/LTO4.
>