3.5.1 Matrix Server Command Reference

Chapter 1: Matrix Server Commands 27

interval is the number of seconds between samplings. The default is one

second. count is the number of samples to make; the default is to sample

indefinitely.

The information displayed for each interval includes the number of I/Os

queued (total block and raw), minimum and maximum latency, count of I/Os,

and average latency. The statistics are organized by I/O, with only actively

used sizes shown.

Latencies are in milliseconds. The minimum and maximum latency is reset

every interval. The number of I/Os queued is an instantaneous value that is

taken at the time of the sample.

NOTE: If interval is too long, the average latency computation may be affected

by 32-bit computer wrap-around. A total of 71 minutes of I/O may be

measured before counter wrap-around. This does not necessarily

equate to 71 minutes in realtime.

Dump I/O statistics in raw format

The rawstat command dumps general I/O statistics for each device in raw

format. The output is typically passed to programs or shell scripts for further

processing. Numbers are the raw counter values, not computed per sample.

The syntax for the command is:

rawstat [<interval> [<count>]] [<psddev>...]

interval is the number of seconds between samplings. The default is one

second. count is the number of samples to make; the default is to sample

indefinitely.

The output consists of ASCII text delimited by carets. The fields are:

1. PSD device name

2. Sample number

3. Sampling interval

4. Number of targets

5. Current active target

6. Number of I/O sizes