PCP-DMCACHE(1)             General Commands Manual            PCP-DMCACHE(1)

NAME         top

       pcp-dmcache, pcp-lvmcache - report on logical storage device caches

SYNOPSIS         top

       pcp [pcp options] dmcache [-i/--iops] [-R/--repeat N] [device ...]

DESCRIPTION         top

       pcp-dmcache reports on the activity of any configured Device Mapper
       Cache targets.  The reported information includes device IOPs, cache
       and metadata device utilization, as well as hit and miss rates and
       ratios for both reads and writes for each cache device.

       pcp-lvmcache (Logical Volume Manager cache) is an exact synonym for
       pcp-dmcache (Device Mapper cache).

       When invoked via the pcp(1) command, the -h/--host, -a/--archive,
       -O/--origin, -s/--samples, -t/--interval, -Z/--timezone and several
       other pcp options become indirectly available.

       By default, pcp-dmcache reports on all available cache target devices
       (one line each, per sample), but this can be restricted to specific
       devices on the command line.

OPTIONS         top

       Additional options are available for changing the output displayed by
       pcp-dmcache.

       -i/--iops displays total read and write operations instead of the
       default cache hit ratio.

       -R/--repeat changes the frequency at which the column heading is
       displayed.  By default, a header is displayed after every tenth
       sample.

SEE ALSO         top

       pcp(1), pmdadm(1), dmsetup(1), PCPIntro(1) and lvmcache(7).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at ⟨http://www.pcp.io/⟩.
       If you have a bug report for this manual page, send it to
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       man-pages@man7.org

Performance Co-Pilot                 PCP                      PCP-DMCACHE(1)

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