Displaying filer statistics

Use the sysstat and uptime commands

You use the sysstat and uptime commands to display filer statistics.

About the sysstat command

The sysstat command displays information about CPU utilization, file operations, read and write operations on disks and tapes, and the age of data in the cache buffer. By default, the filer displays statistics every 15 seconds; you can specify the interval, in seconds, at which statistics are displayed.

The sysstat output is particularly useful for revealing file access patterns on your filer, from which you can determine whether you should install more NVRAM, system memory, or disks.

Depending on the applications that access the filer, the computers on the network, and the network configuration, the following suggested actions might improve your filer's performance:

Typically, 2 MB of NVRAM is sufficient for a system with one SCSI channel. However, if the Disk Kb/s write column shows that the filer writes to disks almost every second, adding NVRAM might help improve system performance. If there are short spurts of writes, adding NVRAM does not improve system throughput. See the hardware guide for your filer model for information about how much additional NVRAM you can install.
The data in the Cache age column indicates how fast read operations are cycling through system memory. If the values in the Cache age column are consistently below 5, the filer might benefit from more system memory. Cache age shows the age of the oldest read-only blocks in memory. A low cache age means that the filer is retrieving information from disk instead of from memory. For information about adding memory, see "About the uptime command." If the CPU utilization percentage in the CPU column is low but you are not getting the expected performance, you might need to add disks to the system.
If CPU utilization is high, you might need to add another filer.
If the network traffic shown in the Net Kb/s column is at or near the capacity of the network interfaces (1 MB per Ethernet adapter and 10 MB per FDDI adapter), you might need to add another network adapter card to the system.

About the uptime command

The uptime command prints the current time, the length of time the system has been up, and the total number of NFS operations the system has performed since it was last booted.

Example

An example of the display is

uptime

8:54am up 2 days 22:23, 3122520 NFS ops

Part No. 210-02334
File: stats4.htm
Last updated: 04/26/99 08:11:56