ZFS - benchmark & tuning before and after doubling RAM

[Dan Langille]

I've been running a ZFS array for about 10 months on a system with 4GB 
of RAM.  I'm about to add another 4GB of RAM.

I think this might be an opportune time to run some simple benchmarks 
and do some tuning.  Getting more out of the system is not a priority 
for me.  It does what I need now.  However, I do see some merit in 
writing something up for others to see/follow/learn.

The system is running FreeBSD 8.2-PRERELEASE #1: Tue Nov 30 22:07:59 EST 
2010 on a 64 bit box.  The ZFS array consists of 7x2TB commodity drives 
on two SiI3124 SATA controllers.  The OS runs off a gmirror RAID-1.

More details here: http://www.freebsddiary.org/zfs-benchmark.php

First, up, I've done a simple bonnie++ benchmark before I add more RAM. 
  I ran this on two different datasets; one with compression enabled, 
one without.

If anyone has suggestions for various tests, option settings, etc, I'm 
happy to run them and include the results.  We have lots of time to play 
with this.

-- 
Dan Langille - http://langille.org/