NAME

       arcstat — report ZFS ARC and L2ARC statistics

SYNOPSIS

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

DESCRIPTION

       arcstat prints various ZFS ARC and L2ARC statistics in vmstat-like fashion:
             c        ARC target size
             dh%      Demand hit percentage
             di%      Demand I/O hit percentage
             dm%      Demand miss percentage
             ddh%     Demand data hit percentage
             ddi%     Demand data I/O hit percentage
             ddm%     Demand data miss percentage
             dmh%     Demand metadata hit percentage
             dmi%     Demand metadata I/O hit percentage
             dmm%     Demand metadata miss percentage
             mfu      MFU list hits per second
             mh%      Metadata hit percentage
             mi%      Metadata I/O hit percentage
             mm%      Metadata miss percentage
             mru      MRU list hits per second
             ph%      Prefetch hits percentage
             pi%      Prefetch I/O hits percentage
             pm%      Prefetch miss percentage
             pdh%     Prefetch data hits percentage
             pdi%     Prefetch data I/O hits percentage
             pdm%     Prefetch data miss percentage
             pmh%     Prefetch metadata hits percentage
             pmi%     Prefetch metadata I/O hits percentage
             pmm%     Prefetch metadata miss percentage
             dhit     Demand hits per second
             dioh     Demand I/O hits per second
             dmis     Demand misses per second
             ddhit    Demand data hits per second
             ddioh    Demand data I/O hits per second
             ddmis    Demand data misses per second
             dmhit    Demand metadata hits per second
             dmioh    Demand metadata I/O hits per second
             dmmis    Demand metadata misses per second
             hit%     ARC hit percentage
             hits     ARC hits per second
             ioh%     ARC I/O hits percentage
             iohs     ARC I/O hits per second
             mfug     MFU ghost list hits per second
             mhit     Metadata hits per second
             mioh     Metadata I/O hits per second
             miss     ARC misses per second
             mmis     Metadata misses per second
             mrug     MRU ghost list hits per second
             phit     Prefetch hits per second
             pioh     Prefetch I/O hits per second
             pmis     Prefetch misses per second
             pdhit    Prefetch data hits per second
             pdioh    Prefetch data I/O hits per second
             pdmis    Prefetch data misses per second
             pmhit    Prefetch metadata hits per second
             pmioh    Prefetch metadata I/O hits per second
             pmmis    Prefetch metadata misses per second
             read     Total ARC accesses per second
             time     Current time
             size     ARC size
             arcsz    Alias for size
             unc      Uncached list hits per second
             dread    Demand accesses per second
             ddread   Demand data accesses per second
             dmread   Demand metadata accesses per second
             eskip    evict_skip per second
             miss%    ARC miss percentage
             mread    Metadata accesses per second
             pread    Prefetch accesses per second
             pdread   Prefetch data accesses per second
             pmread   Prefetch metadata accesses per second
             l2hit%   L2ARC access hit percentage
             l2hits   L2ARC hits per second
             l2miss   L2ARC misses per second
             l2read   Total L2ARC accesses per second
             l2pref   L2ARC prefetch allocated size per second
             l2pref%  L2ARC prefetch allocated size percentage
             l2mfu    L2ARC MFU allocated size per second
             l2mfu%   L2ARC MFU allocated size percentage
             l2mru    L2ARC MRU allocated size per second
             l2mru%   L2ARC MRU allocated size percentage
             l2data   L2ARC data (buf content) allocated size per second
             l2data%  L2ARC data (buf content) allocated size percentage
             l2meta   L2ARC metadata (buf content) allocated size per second
             l2meta%  L2ARC metadata (buf content) allocated size percentage
             l2size   Size of the L2ARC
             mtxmis   mutex_miss per second
             l2bytes  Bytes read per second from the L2ARC
             l2miss%  L2ARC access miss percentage
             l2asize  Actual (compressed) size of the L2ARC
             grow     ARC grow disabled
             need     ARC reclaim needed
             free     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.
             avail    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.

OPTIONS

       -a  Print all possible stats.

       -f  Display only specific fields.  See “DESCRIPTION” for supported statistics.

       -h  Display help message.

       -o  Report statistics to a file instead of the standard output.

       -p  Disable auto-scaling of numerical fields (for raw, machine-parsable values).

       -s  Display data with a specified separator (default: 2 spaces).

       -x  Print extended stats (same as -f time,mfu,mru,mfug,mrug,eskip,mtxmis,dread,pread,read).

       -v  Show field headers and definitions

OPERANDS

       The following operands are supported:
             interval  Specify the sampling interval in seconds.
             count     Display only count reports.

OpenZFS                                         December 23, 2022                                     ARCSTAT(1)