NAME

       cache_writeback - writeback dirty blocks to the origin device.

SYNOPSIS

       cache_writeback [options] --metadata-device {device|file} --origin-device {device|file} --fast-device {device|file}

DESCRIPTION

       cache_writeback  is  an  offline  tool  that  writes  back  dirty  data to the data device
       (origin). Intended for use in recovery scenarios when the SSD is giving IO errors.

       This tool cannot be run on a live cache.

OPTIONS

       -h, --help
              Print help and exit.

       -V, --version
              Print version information and exit.

       --metadata-device {device|file}
              Location of cache metadata.

       --origin-device {device|file}
              Slow device being cached.

       --fast-device {device|file}
              Fast device containing the data that needs to be written back.

       --no-metadata-update
              Do not update the metadata to clear the dirty flags.

           You may want to use this flag if you're decommissioning the cache.

       --buffer-size-meg {size}
              Specify the size for the metadata cache.

           Defaults to 16 Gig, a larger size may improve performance.

       --list-failed-blocks
              List any blocks that failed the writeback process.

SEE ALSO

       cache_dump(8), cache_check(8), cache_repair(8), cache_restore(8)

AUTHOR

       Joe Thornber <ejt@redhat.com>