RE: [squid-users] squid use entire disk partition

From: Adrian Chadd
>On Wed, Aug 09, 2006, Odhiambo WASHINGTON wrote:
> * On 09/08/06 10:51 +0800, huang mingyou wrote:
> | hello,list
> | I want add a 5.6G disk into my squid cache_dir,and I fond
> | that the squid.conf say that if you want use entire disk,you need
> | set 20% size of that disk.Don NOT use the size of that disk.
> | But, Why? :-)

>It boils down to fragmentation. If you use most (80-100%) of your disk
then when you run the disk at capacity it won't be able to allocate
objects anywhere near as optimally >as it can when the disk is at least
half empty. The biggest thing that'll hit your performance is
fragmentation.

>That said, 20% is a bit silly. I'd go with ~50-70%. Anything more and you
definitely are asking for trouble.

Out of curiosity, has anyone done benchmarking of squid using a formatted
disk partition for cache, versus raw IO (using Veritas Volume Manager
etc)? I've seen massive improvements in RDBMS applications
(Oracle/DB2/etc) when using raw IO, so I'm curious if this is even
possible with squid. I'm offline ATM so googling isn't really an option,
but if anyone has links to any case studies etc with Squid, I'm very
interested.

Cheers,

James