Re: RAID or no RAID

Heinz Ahrens wrote:

> What is better:
>
> RAID0 or squid.conf like this:
>
> cache_dir /usr/local/squid/cache1 15000 16 256
> cache_dir /usr/local/squid/cache2 15000 16 256
> cache_dir /usr/local/squid/cache3 15000 16 256

From a performance point of view there shouldn't be a noticeable
difference I think.

From a managing point of view separate drives are probably better, as it
allows you to recover the rest of the cache in case a drive should fail.

For Squid-1.X RAID0 was to preferer (or actually concatenation, not
striping), as it usually allows you to extend the filesystem if needed.
Squid 1.X did not allow you to add/remove cache directories while
preserving your cache.

> I think RAID5 is no alternative, or ???

Squid has about the worst I/O pattern for RAID5 performance.. lots of
small random writes.

--
Henrik Nordstrom
Squid hacker