On Dec 12, 2006, at 13:32 , Michael Stone wrote:
On Tue, Dec 12, 2006 at 12:29:29PM +0100, Alexander Staubo wrote:
I suspect the hardware's real maximum performance of the system
is ~150 tps, but that the LSI's write cache is buffering the
writes. I would love to validate this hypothesis, but I'm not
sure how.
With fsync off? The write cache shouldn't really matter in that
case. (And for this purpose that's probably a reasonable
configuration.)
No, fsync=on. The tps values are similarly unstable with fsync=off,
though -- I'm seeing bursts of high tps values followed by low-tps
valleys, a kind of staccato flow indicative of a write caching being
filled up and flushed.
Alexander.
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