zilstat.1

ZILSTAT(1)

General Commands Manual

ZILSTAT(1)

NAME

zilstat — report ZFS Intent Log statistics

SYNOPSIS

zilstat [-v] [-a|-p pool|-d dataset[,dataset…]] [-f field[,field…]] [-s separator] [-i interval]

DESCRIPTION

zilstat prints statistics about the ZFS Intent Log (ZIL). The ZIL is used to log synchronous write operations and is replayed on pool import if the system crashes before those writes are committed to the main pool.

By default, global ZIL statistics are displayed. When a pool or dataset is specified, per-dataset statistics are shown instead.

If an interval is specified, the output is repeated every interval seconds showing the change in values since the previous sample. Without an interval, cumulative values are displayed.

The following fields are available:

time: Current time
pool: Pool name
ds: Dataset name
obj: Objset ID
cc: Commit count
cwc: Commit writer count
cec: Commit error count
csc: Commit stall count
cSc: Commit suspend count
cCc: Commit crash count
ic: In-transaction count
iic: Indirect in-transaction count
iib: Indirect in-transaction bytes
icc: Copied in-transaction count
icb: Copied in-transaction bytes
inc: Needcopy in-transaction count
inb: Needcopy in-transaction bytes
idc: Direct (copied + needcopy) count
idb: Direct (copied + needcopy) bytes
iwc: Total write (indirect + direct) count
iwb: Total write (indirect + direct) bytes
imnc: Normal metaslab count
imnb: Normal metaslab bytes
imnw: Normal metaslab write bytes
imna: Normal metaslab alloc bytes
imsc: SLOG metaslab count
imsb: SLOG metaslab bytes
imsw: SLOG metaslab write bytes
imsa: SLOG metaslab alloc bytes
imc: Total metaslab (normal + SLOG) count
imb: Total metaslab (normal + SLOG) bytes
imw: Total metaslab (normal + SLOG) write bytes
ima: Total metaslab (normal + SLOG) alloc bytes
se%: Space efficiency percentage (bytes / alloc)
sen%: Normal space efficiency percentage
ses%: SLOG space efficiency percentage
te%: Total efficiency percentage (bytes / write)
ten%: Normal total efficiency percentage
tes%: SLOG total efficiency percentage

OPTIONS

-h: Display a help message.
-a: Print statistics for all datasets across all pools.
-d dataset: Print statistics for the specified dataset(s). Multiple datasets may be given as a comma-separated list.
-f field: Display only the specified fields. Multiple fields may be given as a comma-separated list. See DESCRIPTION for available fields.
-i interval: Print statistics every interval seconds. Values are reported as rates per second.
-p pool: Print statistics for all datasets in the specified pool.
-s separator: Override the default field separator (two spaces) with a custom string.
-v: List all available field headers and their definitions.

ENVIRONMENT

Linux: Statistics are read from /proc/spl/kstat/zfs/zil for global stats and from per-pool objset files under /proc/spl/kstat/zfs/pool/.
FreeBSD: Statistics are read via sysctl(8) from the kstat.zfs tree.