On Tue, 26 Feb 2013, hagai wrote:
for what is worth..
I had the same problem and found the answer here -
Given enough sequential I/O requests, zfs mirrors behave every much
like RAID-0 for reads. Sequential prefetch is very important in order
to avoid the latencies.
While this script may not work perfectly as is for FreeBSD, it was
very good at discovering a zfs performance bug (since corrected) and
is still an interesting exercise for zfs to see how ZFS ARC caching
helps for re-reads. See
The script will exercise an initial uncached read from disks, and then
a (hopefully) cached re-read from disks. I think that it serves as a
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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