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.
Additional options are available for changing the output displayed by
-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
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
firstname.lastname@example.org. This page was obtained from the project's upstream
Git repository ⟨git://git.pcp.io/pcp⟩ on 2017-03-13. If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
Performance Co-Pilot PCP PCP-DMCACHE(1)