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 data cache, in megabytes.

    Defaults to 64 MiB, 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>
