cache_writeback (8) - Linux Manuals

cache_writeback: writeback dirty blocks to the origin device.


cache_writeback - writeback dirty blocks to the origin device.


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


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.


-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.
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 any blocks that failed the writeback process.


Joe Thornber <ejt [at]>