Add request size histograms (-r) to zpool iostat, minor man page fix
Add -r option to "zpool iostat" to print request size histograms for the leaf
ZIOs. This includes histograms of individual ZIOs ("ind") and aggregate ZIOs
("agg"). These stats can be useful for seeing how well the ZFS IO aggregator
is working.
$ zpool iostat -r
mypool sync_read sync_write async_read async_write scrub
req_size ind agg ind agg ind agg ind agg ind agg
---------- ----- ----- ----- ----- ----- ----- ----- ----- ----- -----
512 0 0 0 0 0 0 530 0 0 0
1K 0 0 260 0 0 0 116 246 0 0
2K 0 0 0 0 0 0 0 431 0 0
4K 0 0 0 0 0 0 3 107 0 0
8K 15 0 35 0 0 0 0 6 0 0
16K 0 0 0 0 0 0 0 39 0 0
32K 0 0 0 0 0 0 0 0 0 0
64K 20 0 40 0 0 0 0 0 0 0
128K 0 0 20 0 0 0 0 0 0 0
256K 0 0 0 0 0 0 0 0 0 0
512K 0 0 0 0 0 0 0 0 0 0
1M 0 0 0 0 0 0 0 0 0 0
2M 0 0 0 0 0 0 0 0 0 0
4M 0 0 0 0 0 0 155 19 0 0
8M 0 0 0 0 0 0 0 811 0 0
16M 0 0 0 0 0 0 0 68 0 0
--------------------------------------------------------------------------------
Also rename the stray "-G" in the man page to be "-w" for latency histograms.
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #4659