On 07/19/12 18:24, Traffanstead, Mike wrote:
iozone doesn't vary the blocksize during the test, it's a very
artificial test but it's useful for gauging performance under
So for this test all of the writes would have been 64k blocks, 128k,
etc. for that particular step.
Just as another point of reference I reran the test with a Crucial M4
SSD and the results for 16G/64k were 35mB/s (x5 improvement).
I'll rerun that part of the test with zpool iostat and see what it says.
For random writes to work without forcing a lot of read i/o and
read-modify-write sequences, set the recordsize on the filesystem used
for the test to match the iozone recordsize. For instance:
zfs set recordsize=64k $fsname
and ensure that the files used for the test are re-created after you
make this setting change ("recordsize" is sticky at file creation time).
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