cache-clean (1) - Linux Manuals
cache-clean: Administration tool for the A-REX cache.
NAME
cache-clean - Administration tool for the A-REX cache.
SYNOPSIS
cache-clean [-h] [-s] [-S] [-m NN -M NN] [-E N] [-D debug_level]
cache-clean
is a tool for administrators of ARC server installations to safely
remove A-REX cache data and to provide an overview of the contents of
the cache. It is used by the A-REX to automatically manage cache
contents.
There are two modes of operation - printing statistics and deleting files.
If
-s
is used, then statistics are printed on each cache. If
-m
and
-M
are used then files in each cache are deleted if the space used by the cache on
the file system is more than that given by
-M,
in the order of least recently accessed, until the space used by the cache is equal
to what is specified by
-m.
If
-E
is used, then all files accessed less recently than the given time are
deleted.
-E
can be used in combination with
-m
and
-M
but deleting files using
-E
is carried out first. If after this the cache used space is still more
than that given by
-M
then cleaning according to those options is performed.
If the cache is on a file system shared with other data then
-S
should be specified so that the space used by the cache is calculated. Otherwise
all the used space on the file system is assumed to be for the cache. Using
-S
is slower so should only be used when the cache is shared.
By default the "df" command is used to determine total and (if
-S
is not specified) used space. If this command is not supported on the cache
file system then
-f
can be used to specify an alternate command. The output of this command must be
"total_bytes used_bytes", and so the command would normally be a small script
around the file system space information tool. The cache directory is passed as
the last argument to this command.
Cache directories are given by
dir1, dir2..
or taken from the config file specified by
-c
or the ARC_CONFIG environment variable.
-h
- print short help
-s
- print cache statistics, without deleting anything. The output displays
for each cache the number of deletable (and locked) files, the total size of
these files, the percentage usage of the file system in which the cache is
stored, and a histogram of access times of the files in the cache.
-S
- Calculate the size of the cache instead of taking used space on the file
system. This should only be used when the cache file system is shared with
other data.
-M
- the maximum used space (as % of the file system) at which to start cleaning
-m
- the minimum used space (as % of the file system) at which to stop cleaning
-E
- files accessed less recently than the given time period will be
deleted. Example values of this option are 1800, 90s, 24h,
30d. The default when no suffix is given is seconds.
-f
- alternative command to "df" for obtaining the file system total and used
space. The output of this command must be "total_bytes used_bytes". The cache
directory is passed as the last argument to this command.
-D
- debug level. Possible values are FATAL, ERROR, WARNING, INFO,
VERBOSE or DEBUG. Default level is INFO.
-c
- path to an A-REX config file, xml or ini format
This tool is run periodically by the A-REX to keep the size of each
cache within the limits specified in the configuration file. Therefore
cleaning should not be performed manually, unless the cache size needs
to be reduced temporarily. For performance reasons it may however be
desirable to run cache-clean independently on the machine hosting the
cache file system, if this is different from the A-REX host. The most
useful function for administrators is to give an overview of the
contents of the cache, using the
-s
option.
Within each cache directory specified in the configuration file, there is
a subdirectory for data (data/) and one for per-job hard links (joblinks/).
See the A-REX Administration Guide for more details.
cache-clean
should only operate on the data subdirectory, therefore when giving
dir
arguments they should be the top level cache directory.
cache-clean
will then automatically only look at files within the data directory.
cache-clean -m20 -M30 -E30d -D VERBOSE -c /etc/arc.conf
Cache directories are taken from the configuration file
/etc/arc.conf
and all cache files accessed more than 30 days ago are deleted. Then
if the used space in a cache is above 30%, data is deleted until the
used space reaches 20%. Verbose debug output is enabled so information
is output on each file that is deleted.
APACHE LICENSE Version 2.0
ARC software is developed by the NorduGrid Collaboration
(http://www.nordugrid.org), please consult the AUTHORS file distributed with
ARC. Please report bugs and feature requests to http://bugzilla.nordugrid.org
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