arcstat.1

ARCSTAT(1) General Commands Manual ARCSTAT(1)

arcstat — report ZFS ARC and L2ARC statistics

arcstat [-havxp] [-f field[,field…]] [-o file] [-s string] [interval] [count]

arcstat prints various ZFS ARC and L2ARC statistics in vmstat-like fashion:

ARC target size
Demand hit percentage
Demand I/O hit percentage
Demand miss percentage
Demand data hit percentage
Demand data I/O hit percentage
Demand data miss percentage
Demand metadata hit percentage
Demand metadata I/O hit percentage
Demand metadata miss percentage
MFU list hits per second
Metadata hit percentage
Metadata I/O hit percentage
Metadata miss percentage
MRU list hits per second
Prefetch hits percentage
Prefetch I/O hits percentage
Prefetch miss percentage
Prefetch data hits percentage
Prefetch data I/O hits percentage
Prefetch data miss percentage
Prefetch metadata hits percentage
Prefetch metadata I/O hits percentage
Prefetch metadata miss percentage
Demand hits per second
Demand I/O hits per second
Demand misses per second
Demand data hits per second
Demand data I/O hits per second
Demand data misses per second
Demand metadata hits per second
Demand metadata I/O hits per second
Demand metadata misses per second
ARC hit percentage
ARC hits per second
ARC I/O hits percentage
ARC I/O hits per second
MFU ghost list hits per second
Metadata hits per second
Metadata I/O hits per second
ARC misses per second
Metadata misses per second
MRU ghost list hits per second
Prefetch hits per second
Prefetch I/O hits per second
Prefetch misses per second
Prefetch data hits per second
Prefetch data I/O hits per second
Prefetch data misses per second
Prefetch metadata hits per second
Prefetch metadata I/O hits per second
Prefetch metadata misses per second
Total ARC accesses per second
Current time
ARC size
Alias for size
Uncached list hits per second
Demand accesses per second
Demand data accesses per second
Demand metadata accesses per second
evict_skip per second
ARC miss percentage
Metadata accesses per second
Prefetch accesses per second
Prefetch data accesses per second
Prefetch metadata accesses per second
L2ARC access hit percentage
L2ARC hits per second
L2ARC misses per second
Total L2ARC accesses per second
L2ARC prefetch allocated size per second
L2ARC prefetch allocated size percentage
L2ARC MFU allocated size per second
L2ARC MFU allocated size percentage
L2ARC MRU allocated size per second
L2ARC MRU allocated size percentage
L2ARC data (buf content) allocated size per second
L2ARC data (buf content) allocated size percentage
L2ARC metadata (buf content) allocated size per second
L2ARC metadata (buf content) allocated size percentage
Size of the L2ARC
mutex_miss per second
Bytes read per second from the L2ARC
L2ARC access miss percentage
Actual (compressed) size of the L2ARC
ARC grow disabled
ARC reclaim needed
The ARC's idea of how much free memory there is, which includes evictable memory in the page cache. Since the ARC tries to keep avail above zero, avail is usually more instructive to observe than free.
The ARC's idea of how much free memory is available to it, which is a bit less than free. May temporarily be negative, in which case the ARC will reduce the target size c.

Print all possible stats.
Display only specific fields. See DESCRIPTION for supported statistics.
Display help message.
Report statistics to a file instead of the standard output.
Disable auto-scaling of numerical fields (for raw, machine-parsable values).
Display data with a specified separator (default: 2 spaces).
Print extended stats (same as -f time,mfu,mru,mfug,mrug,eskip,mtxmis,dread,pread,read).
Show field headers and definitions

The following operands are supported:

interval
Specify the sampling interval in seconds.
count
Display only count reports.
December 23, 2022 Debian