arcstat

ARCSTAT(1) General Commands Manual ARCSTAT(1)

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)