10 messages in org.freebsd.freebsd-performanceDisk I/O Performance| From | Sent On | Attachments |
|---|---|---|
| Kristofer Pettijohn | Oct 19, 2004 12:34 pm | |
| João Carlos Mendes Luís | Oct 19, 2004 12:45 pm | |
| Mike Horwath | Oct 19, 2004 1:52 pm | |
| Kristofer Pettijohn | Oct 19, 2004 2:01 pm | |
| Kristofer Pettijohn | Oct 19, 2004 2:02 pm | |
| Mike Horwath | Oct 19, 2004 2:02 pm | |
| Mike Horwath | Oct 19, 2004 2:04 pm | |
| Kristofer Pettijohn | Oct 19, 2004 2:06 pm | |
| Mike Jakubik | Oct 19, 2004 2:08 pm | |
| João Carlos Mendes Luís | Oct 20, 2004 8:33 am |
| Subject: | Disk I/O Performance | |
|---|---|---|
| From: | Mike Horwath (drec...@Geeks.ORG) | |
| Date: | Oct 19, 2004 2:04:38 pm | |
| List: | org.freebsd.freebsd-performance | |
On Tue, Oct 19, 2004 at 04:02:41PM -0500, Kristofer Pettijohn wrote:
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.
The old idea from someone long ago was to set the stripe size the size of the cylinder block. I found 8MB to be pretty decent, though not perfect.
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.
Use this for tunefs - it made a little bit of a difference:
tunefs -m 8 -o time /dev/something
and make sure you set up the dspool.ctl file correctly because of the change.
-- Mike Horwath, reachable via drec...@Geeks.ORG