Shridhar Daithankar wrote:
> I might have found the bottleneck, although by accident. Mysql was running out
> of space while creating index. So my friend shut down mysql and tried to move
> things by hand to create links. He noticed that even things like cp were
> terribly slow and it hit us.. May be the culprit is the file system. Ext3 in
> this case.
I just added a file system and multi-cpu section to my performance
tuning paper:
http://www.ca.postgresql.org/docs/momjian/hw_performance/
The paper does recommend ext3, but the differences between file systems
are very small. If you are seeing 'cp' as slow, I wonder if it may be
something more general, like poorly tuned hardware or something. You can
use 'dd' to throw some data around the file system and see if that is
showing slowness; compare those numbers to another machine that has
different hardware/OS.
Also, though ext3 is slower, turning fsync off should make ext3 function
similar to ext2. That would be an interesting test if you suspect ext3.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
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