Specifications

time of a hard disk, about 10 milliseconds, with the 10 nanoseconds access
time of the newer RAM memories)
Every object in RAM memory has a size of 72 bytes (for “small” pointer
architectures like Intel, Sparc, or MIPS. For Alpha, it is 104 bytes). If the
average size of an object on the Internet is about 8 KB and we have 1 GB
disk for the cache, we will be storing about 130,000 objects, resulting in close
to 10 MB RAM only for meta data.
Squid also holds data in memory for lots of other stuff, such as a table with
all used IP adresses, a fully qualified domain name cache, hot objects (the
most requested), buffers, and access control lists.
It is very important to have more than enough memory for the Squid process,
because, if it has to be swapped, the system performance will be dramatically
reduced.
CPU
Squid is not a program that requires intensive CPU usage. The load of the
processor is only increased while the contents of the cache are being loaded
or checked. Using a multiprocessor machine does not increase the perfor-
mance of the system. To increase efficiency, it is better to buy faster disks or
add more memory.
Some examples of configured systems running Squid are available at http:
//wwwcache.ja.net/servers/squids.html.
Starting Squid
Squid is already preconfigured in SuSE Linux, so you can start it easily right
after installation. A prerequisite for a smooth start is an already configured
network, at least one name server and, of course, Internet access. Problems
can arise if a dial-up connection is used with dynamic DNS configuration. In
cases such as this, at least the name server should be entered clearly, because
Squid will not start if it does not detect a DNS in the /etc/resolv.conf.
To start Squid, enter rcsquid start at the command line at root. For
the initial start-up, the directory structure will first have to be defined in
/var/squid/cache. This is done by the start script /etc/init.d/squid
automatically and can take a few seconds or even minutes. If done appears
to the right in green, Squid has been successfully loaded. Test Squid’s func-
tionality on the local system by entering localhost and Port 3128 as
172 Starting Squid