Disk I/O Performance
Kristofer Pettijohn
krishopper at cybernetik.net
Tue Oct 19 14:02:43 PDT 2004
On Tue, Oct 19, 2004 at 04:45:03PM -0300, Jo?o Carlos Mendes Lu?s wrote:
> I'd say that you have to check which CCD chunk size is best for
> your needs. The manual for vinum recommends avoiding chunk sized to a
> power of two, which is probably the first big mistake of everybody.
I've tried a wide range of chunk sizes, from 128kB to 64MB.. also have
been avoiding powers of 2.
> Try mounting with option noatime, if you haven't already. And use
> the largest block size possible when formatting. Last time I read about
> there was a limit of 16384, but I would expect better performance for
> large file with 64k blocks (and 8k frags).
The largest block size is 64k, and I have done that as well.
> If you don't have a need for safety on the files, you could try
> mount async and measure if it suits better you need for performance than
> softupdates. Sometimes softupdates is faster, and it is always safer.
Unfortunately, the files do need a bit of safety.I did think about
async, but I fear the worst to happen.
Kristofer
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