Displays logical I/O statistics for the given pools/vdevs.
Physical I/O statistics may be observed via
iostat(1).
If writes are located nearby, they may be merged into a single
larger operation.
Additional I/O may be generated depending on the level of vdev redundancy.
To filter output, you may pass in a list of pools, a pool and list of vdevs
in that pool, or a list of any vdevs from any pool.
If no items are specified, statistics for every pool in the system are shown.
When given an
interval,
the statistics are printed every
interval
seconds until killed.
If
-n
flag is specified the headers are displayed only once, otherwise they are
displayed periodically.
If
count
is specified, the command exits after
count
reports are printed.
The first report printed is always the statistics since boot regardless of whether
interval
and
count
are passed.
However, this behavior can be suppressed with the
-y
flag.
Also note that the units of
K,
M,
Gâ¦
that are printed in the report are in base 1024.
To get the raw values, use the
-p
flag.
|
| -c [SCRIPT1[,SCRIPT2 ]â¦]
|
| |
Run a script (or scripts) on each vdev and include the output as a new column
in the
zpool
output.
Users can run any script found in their
~/.zpool.d
directory or from the system
/etc/zfs/zpool.d
directory.
Script names containing the slash
( /)
character are not allowed.
The default search path can be overridden by setting the
ZPOOL_SCRIPTS_PATH
environment variable.
A privileged user can only run
-c
if they have the
ZPOOL_SCRIPTS_AS_ROOT
environment variable set.
If a script requires the use of a privileged command, like
smartctl(8),
then it's recommended you allow the user access to it in
/etc/sudoers
or add the user to the
/etc/sudoers.d/zfs
file.
If
-c
is passed without a script name, it prints a list of all scripts.
-c
also sets verbose mode
amp;(-v amp;).
Script output should be in the form of "name=value".
The column name is set to "name" and the value is set to "value".
Multiple lines can be used to output multiple columns.
The first line of output not in the
"name=value" format is displayed without a column title,
and no more output after that is displayed.
This can be useful for printing error messages.
Blank or NULL values are printed as a '-' to make output AWKable.
The following environment variables are set before running each script:
|
| VDEV_PATH
|
Full path to the vdev
|
| VDEV_UPATH
|
Underlying path to the vdev
( /dev/sd*).
For use with device mapper, multipath, or partitioned vdevs.
|
| VDEV_ENC_SYSFS_PATH
|
The sysfs path to the enclosure for the vdev (if any).
|
|
| -T u| d
|
Display a time stamp.
Specify
u
for a printed representation of the internal representation of time.
See
time(2).
Specify
d
for standard date format.
See
date(1).
|
| -g
|
Display vdev GUIDs instead of the normal device names.
These GUIDs can be used in place of device names for the zpool
detach/offline/remove/replace commands.
|
| -H
|
Scripted mode.
Do not display headers, and separate fields by a
single tab instead of arbitrary space.
|
| -L
|
Display real paths for vdevs resolving all symbolic links.
This can be used to look up the current block device name regardless of the
/dev/disk/
path used to open it.
|
| -n
|
Print headers only once when passed
|
| -p
|
Display numbers in parsable (exact) values.
Time values are in nanoseconds.
|
| -P
|
Display full paths for vdevs instead of only the last component of the path.
This can be used in conjunction with the
-L
flag.
|
| -r
|
Print request size histograms for the leaf vdev's I/O.
This includes histograms of individual I/O (ind) and aggregate I/O (agg).
These stats can be useful for observing how well I/O aggregation is working.
Note that TRIM I/O may exceed 16M, but will be counted as 16M.
|
| -v
|
Verbose statistics Reports usage statistics for individual vdevs within the
pool, in addition to the pool-wide statistics.
|
| -y
|
Normally the first line of output reports the statistics since boot:
suppress it.
|
| -w
|
Display latency histograms:
|
| total_wait
|
Total I/O time (queuing + disk I/O time).
|
| disk_wait
|
Disk I/O time (time reading/writing the disk).
|
| syncq_wait
|
Amount of time I/O spent in synchronous priority queues.
Does not include disk time.
|
| asyncq_wait
|
Amount of time I/O spent in asynchronous priority queues.
Does not include disk time.
|
| scrub
|
Amount of time I/O spent in scrub queue.
Does not include disk time.
|
|
| -l
|
Include average latency statistics:
|
| total_wait
|
Average total I/O time (queuing + disk I/O time).
|
| disk_wait
|
Average disk I/O time (time reading/writing the disk).
|
| syncq_wait
|
Average amount of time I/O spent in synchronous priority queues.
Does not include disk time.
|
| asyncq_wait
|
Average amount of time I/O spent in asynchronous priority queues.
Does not include disk time.
|
| scrub
|
Average queuing time in scrub queue.
Does not include disk time.
|
| trim
|
Average queuing time in trim queue.
Does not include disk time.
|
|
| -q
|
Include active queue statistics.
Each priority queue has both pending
( pend)
and active
( activ)
I/O requests.
Pending requests are waiting to be issued to the disk,
and active requests have been issued to disk and are waiting for completion.
These stats are broken out by priority queue:
|
| syncq_read/write
|
Current number of entries in synchronous priority
queues.
|
| asyncq_read/write
|
Current number of entries in asynchronous priority queues.
|
| scrubq_read
|
Current number of entries in scrub queue.
|
| trimq_write
|
Current number of entries in trim queue.
|
|
All queue statistics are instantaneous measurements of the number of
entries in the queues.
If you specify an interval,
the measurements will be sampled from the end of the interval.
