Re: [squid-users] Squid Caches

Mike Diggins wrote:

> My initial thought was that a stripe set was the obvious choice for the
> squid cache. It seems that isn't the case. Why wouldn't Squid benefit from
> the stripe set?

Because Squid performs small random I/O aldready distributed over the
cache_dir lines you have. It does not need the help of a stripe manager
to distribute the I/O load on more than one disk.

Striped disks are best at high bandwidth sequential read/writes. Squid
performs none of these, nor does it require high disk I/O bandwidth.
What Squid requires is good seek times which you get by having multiple
drives being able to service different requests in parallell.

> Also, if I have, say, two cache dirs spread over two physical disks and
> one drive fails, will squid continue to run with one cache dir out of
> commission?

Yes, but you might have to remove the crashed disks cache_dir line from
squid.conf before Squid is fully happy.

As robert said there is also an effort on squid.sourceforge.net to
improve on this to allow "hot" addition/removal of cache directories,
but the status of this work is unknown.

--
Henrik Nordstrom
Squid Hacker