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.