Disk I/O Performance

[Kristofer Pettijohn]

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