Squid: The Definitive Guide

FreeBSD is another popular Squid platform, and my personal favorite. Table D-2 and Figure D-2 summarize the results for FreeBSD. Again, coss exhibits the highest throughput, followed by diskd . The aufs storage scheme doesn't currently run on FreeBSD. These results come from FreeBSD Version 4.8-STABLE (released April 3, 2003). I built a kernel with the following noteworthy options:

options MSGMNB=16384 options MSGMNI=41 options MSGSEG=2049 options MSGSSZ=64 options MSGTQL=512 options SHMSEG=16 options SHMMNI=32 options SHMMAX=2097152 options SHMALL=4096 options MAXFILES=8192 options NMBCLUSTERS=32768 options VFS_AIO

Table D-2. FreeBSD benchmarking results

Enabling the async , noatime , and softupdate ^[3] options boosts the standard ufs performance from 24 to 38 transactions per second. However, using one of the other storage schemes increases the sustainable throughput even more.

^[3] On FreeBSD, softupdates aren't a mount option, but must be set with the tunefs command.

FreeBSD's diskd performance (129/sec) isn't quite as good as on Linux (169/sec), perhaps because the underlying filesystem ( ext2fs ) is better.

Note that the trace for coss is relatively flat. Its performance doesn't change much over time. Furthermore, both FreeBSD and Linux report similar throughput numbers : 326/sec and 331/sec. This leads me to believe that the disk system isn't a bottleneck in these tests. In fact, the test with no disk cache (see Section D.8) achieves essentially the same throughput (332/sec).