In my last article, I explained how to use squid as part of a
high performance CGI Proxy hosting platform. At one point in the
article, I suggested you use the UFS file system because I
hadn’t resolved issues with the other file systems available in
squid. I’ve spent a few weeks tweaking disk performance in
squid, and have some useful suggestions now. One thing that gave
me helpful insight was the book Squid: The Definitive Guide.
What I found is that I was having an i/o bottleneck on my
servers. Many of my servers have the following disk setup:  2x
500gb samsung sata 2x 500gb western digital sata  The samsung
hard drives just weren’t fast enough, and though my western
digitals were faster, they were still causing issues. Though I
could tend to ignore this issue on my lower end servers, on my
new core2quad intel cpus, I would hit an obvious disk bottleneck
at about 2/3 of what the server could handle cpu wise. I didn’t
want to give up caching, so I had to investigate a few things.
Before I go further, I sho