Uncache

NAME
       uncache - remove cached files from the pagecache

SYNOPSIS
       uncache [-0|--null] [-n|--dry-run] [-v|--verbose]

DESCRIPTION
       uncache  reads  a list of files from standard input and tries to remove
       all cached blocks of these files from the  pagecache.   Files  must  be
       given as absolute file names.  Only regular files will be processed.

       Every  file  will be memory mapped in order to drop the blocks from the
       pagecache.  Therefore unreadable files will be ignored silently.

       The uncache program only drops cached blocks for the named files.  This
       is  in  contrast to the /proc/sys/vm/drop_caches sysctl which will drop
       the cached blocks for all files.

OPTIONS
       -0, --null
              Files read from standard input are terminated by a null  charac-
              ter  instead  of  by  whitespace.  Useful when input items might
              contain white space, quote marks, or backslashes.  The GNU  find
              -print0 option produces input suitable for this mode.

       -n, --dry-run
              Do not actually do anything.  Can be used together with the ver-
              bose option to check which files are currently in the pagecache.

       -v, --verbose
              Verbose  mode.   The  file  name of every file that actually has
              cached blocks will be printed to standard output  together  with
              the number of cached blocks.

FILES
       /proc/sys/vm/drop_caches

BUGS
       The  program  uses  posix_fadvise(2) to notify the kernel that the file
       data will not be accessed in the near future.  This is only  an  advice
       and the kernel may or may not purge blocks from the pagecache.

EXAMPLES
       find /var/lib/mysql -type f | uncache --dry-run --verbose
              Show  which  MySQL data files are currently in the pagecache but
              do not purge the cached blocks.

       find /var/log -type f | uncache
              Remove cached blocks for all files below the /var/log  directory
              from the pagecache.

       find /var/log -type f -print0 | uncache -0
              The  same  as  before  but use zero terminated strings to handle
              unusual file names.