Listing Pool-Wide I/O Statistics
When issued with no options, the zpool iostat
command displays the accumulated statistics since boot for all pools on the system. For example:
$ zpool iostat
capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
rpool 6.05G 61.9G 0 0 786 107
system1 31.3G 36.7G 4 1 296K 86.1K
---------- ----- ----- ----- ----- ----- -----
Because these statistics are cumulative since boot, bandwidth might appear low if the pool is relatively idle. You can request a more accurate view of current bandwidth usage by specifying an interval. For example:
$ zpool iostat system1 2
capacity operations bandwidth
pool alloc free read write read write
---------- ----- ----- ---- ----- ----- -----
system1 18.5G 49.5G 0 187 0 23.3M
system1 18.5G 49.5G 0 464 0 57.7M
system1 18.5G 49.5G 0 457 0 56.6M
system1 18.8G 49.2G 0 435 0 51.3M
In this example, the command displays usage statistics for the pool system1
every two seconds until you press Control-C. Alternately, you can specify an additional count
argument, which causes the command to terminate after the specified number of iterations.
For example, zpool iostat 2 3
would print a summary every two seconds for three iterations, for a total of six seconds.