How to Display Extended Disk Statistics (iostat -xtc) (System Administration Guide, Volume 2)

System Administration Guide, Volume 2

How to Display Extended Disk Statistics (`iostat -xtc`)

Run iostat -xtc to get extended disk statistics.

$ iostat -xtc
                  extended device statistics                      tty         cpu
device       r/s    w/s   kr/s   kw/s wait actv  svc_t  %w  %b  tin tout  us sy wt id
fd0          0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0    0    0   0  0  0 100
sd0          0.0    0.0    0.4    0.4  0.0  0.0   49.5   0   0 
sd6          0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
nfs1         0.0    0.0    0.0    0.0  0.0  0.0    0.0   0   0 
nfs49        0.0    0.0    0.0    0.0  0.0  0.0   15.1   0   0 
nfs53        0.0    0.0    0.4    0.0  0.0  0.0   24.5   0   0 
nfs54        0.0    0.0    0.0    0.0  0.0  0.0    6.3   0   0 
nfs55        0.0    0.0    0.0    0.0  0.0  0.0    4.9   0   0

This command displays a line of output for each disk. The output fields are described in the table below.

Table 36-5 Output From the iostat -xtc Command


Field Name	Description
`r/s`	Reads per second
`w/s`	Writes per second
`Kr/s`	Kbytes read per second
`Kw/s`	Kbytes written per second
`wait`	Average number of transactions waiting for service (queue length)
`actv`	Average number of transactions actively being serviced
`svc_t`	Average service time, in milliseconds
`%w`	Percentage of time the queue is not empty
`%b`	Percentage of time the disk is busy