The System Accounting Records contain statistics of the kernel running on the Steelhead appliance. The most basic ones are the CPU utilization, system load, NIC statistics and memory usage.
The Steelhead appliance keeps track of about a month of SAR data. The SAR data gets generated every day at 23:53 and during the generation of a system dump:
Figure 6.93. Overview of the SAR data files
-rw-r--r-- 1 edwin edwin 1281662 Sep 10 07:53 2012.09.09.23.53.sar -rw-r--r-- 1 edwin edwin 1272770 Sep 11 07:53 2012.09.10.23.53.sar -rw-r--r-- 1 edwin edwin 1281518 Sep 12 07:53 2012.09.11.23.53.sar -rw-r--r-- 1 edwin edwin 872426 Sep 13 00:15 2012.09.12.16.15.sar -rw-r--r-- 1 edwin edwin 1281519 Sep 13 07:53 2012.09.12.23.53.sar
You can use a visualization tool like kSar to graph the data. You can find it at http://sourceforge.net/projects/ksar/.