IOZTAT(8)

💅 ioztat(8) — display logical I/O statistics for ZFS datasets

Hey bestie, welcome to the ioztat(8) page from the System Manager's Manual — it's giving very useful ZFS logical I/O energy ✨

🌸 NAME

ioztat — display logical I/O statistics for ZFS datasets

🦋 SYNOPSIS

ioztat -V | --version
ioztat -h | --help
ioztat [-DeHINnoSxyz] [-c count] [-i interval] [-T u|d]
       [-s name|operations|reads|writes|throughput|nread|nwritten]
       [dataset ...] [interval [count]]

💖 DESCRIPTION

The ioztat utility displays logical I/O statistics for individual ZFS datasets. The first report is averaged over the system uptime unless it's suppressed with -y. If an interval is specified, that first report is followed by reports averaged over the reporting interval. If -y or a count is specified, interval defaults to one second.

Underlying device I/O depends on pool and dataset configuration. See zpool-iostat(8) and iostat(8) for reporting on these values.

To filter output you may pass in a list of datasets. If no datasets are specified, statistics for every mounted dataset in the system are shown. If the -n option is given, child datasets are not included for any specified dataset unless they are also directly specified.

Okay bestie, here are the options — every single one, no skips 🫶

✨ OPTIONS ✨

• -D — Display formatted byte sizes using decimal powers of 1000 instead of powers of 1024.
• -c — Display count reports and exit. This can also be specified after an interval at the end of the argument list. If interval is specified but not count then it defaults to infinity, otherwise it defaults to one.
• -e — Display exact values, without truncating dataset names (unless -p is given) or formatting numeric output.
• -H — Scripted mode, skip headers and tab-separate fields instead of using arbitrary whitespace.
• -h, --help — Display help text and exit.
• -I — Display total statistics since the last report instead of averages per-second.
• -i — Pause interval seconds between reports. This can also be specified at the end of the argument list, prior to an optional count. If no interval is specified the default is 1 second.

The ioztat command will accept non-integer intervals, but it should be noted the reporting interval is not exact.

• -N — Display headers only once, instead of periodically repeating them.
• -n — Omit children of any specified datasets that haven't themselves been explicitly specified.
• -o — Overwrite mode. Before each report, clear the screen and print only as many lines as will fit.
• -P — Display dataset names on a single line.
• -p — Display dataset names as an indented tree spread across multiple lines. These options override defaults that may be applied by different sorting and display modes.
• -S — Sum child dataset statistics into their parents. This can be useful when combined with -n to omit display of child datasets while still seeing associated I/O.
• -s — Sort each report by the specified order. Defaults to name. Choices are name, operations, reads, writes, throughput, nread, nwritten.
• -T u|d — Before each report, display a timestamp. Specify u for a numeric Unix timestamp in seconds since the epoch, or d for a formatted date-time.
• -V, --version — Display the current version of ioztat and exit.
• -x — Specified once, display an opsize group containing throughput divided by operations, giving the average byte size of each I/O. Specified twice, also display an unlinks section giving a count of the number of files and directories queued for deletion, and the number which have been deleted.
• -y — Omit statistics since boot. This suppresses output for the first interval seconds.
• -z — Omit datasets which have no activity.

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🎀 EXAMPLES

ioztat rpool/USERDATA 1

Display per-second statistics for any mounted datasets within rpool/USERDATA.

ioztat -zoTd -s operations 5

Display statistics for all mounted datasets with activity across five second intervals, ordered by total read and write operations, limited by available display and overwriting prior reports in a manner similar to top(1).

ioztat -SIn rpool

Display sum total of I/O for all datasets within rpool since boot.

ioztat -Hey

Display a single one-second report for all mounted datasets, using a machine-readable format omitting headers, using tab-delimited fields, and providing exact values.

🌈 SEE ALSO

iostat(8), zfs(8), zpool-iostat(8)

💀 BUGS

Please report any issues at https://github.com/jimsalterjrs/ioztat/issues

Debian build, January 29, 2022 🎀💖