[squid-users] filesystem performance

A friend of mine sent me this message from postfix-users mailing list:

http://marc.theaimsgroup.com/?l=postfix-users&m=99654359818329&w=2

<quote>
- chattr +S on ext2 costs you 2:1 or 3:1 throughput when compared with
fsync()-on-data and fsync()-on-dir.
- full-journalling ext3 can offer a 3x to 10x improvement over ext2,
depending upon how ext2 is used and the directory layout/task count.
- ext2 likes to have few directories, many processes per directory.
- ext3 likes many directories, few processes per directory.
- We can write data to the journal much faster than we can checkpoint
that data into the main filesystem, so the benefit of an external
journal device (spinning or NVRAM) has not been demonstrated.
</quote>

So, it looks like, for some usage patterns, Ext3 with full data
journalising turned on, can be faster than Ext2!
This is strange, but it's interesting to note that those usage patterns
seem to be close to what Squid does (many directories, few processes per
directory). So maybe someone has some benchmarks with Squid on Ext3? ;-)

-- 
Florin Andrei
"Our kernel does have source control: its name is
Linus Torvalds, CVS with a brain." - Nicholas Knight