On Thu, 17 Feb 2005, Tom Lane wrote:
Christopher Kings-Lynne <[EMAIL PROTECTED]> writes:WinXP fsync = true 20-28 tps WinXP fsync = false 600 tps Linux fsync = true 800 tps Linux fsync = false 980 tps
Wow, that's terrible on Windows. If there's a solution, it'd be nice to backport it...
Actually, the number that's way out of line there is the Linux w/fsync one. I infer that he's got disk write cache enabled and therefore the transactions aren't really being synced to disk at all.
Any claimed TPS rate exceeding your disk drive's rotation rate is a red flag.
Write cache is enabled under Linux by default all the time I make deal with it (since 1993).
It doesn't interfere with fsync(), as linux kernel uses cache flush for fsync.
I have 2.6.10 kernel running *without* any additional patches, and without any specific hdparm settings.
fsync() really works fine as I switch off my notebook everyday 2-3 times, and never had any data loss :)
Related staff from dmesg is
hda: cache flushes supported
Regards, E.R. _________________________________________________________________________ Evgeny Rodichev Sternberg Astronomical Institute email: [EMAIL PROTECTED] Moscow State University Phone: 007 (095) 939 2383 Fax: 007 (095) 932 8841 http://www.sai.msu.su/~er
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