# cache_metadata_size - Estimate the size of the metadata device needed for... - man(8) - [phpMan]

[_cache_metadata_size_(8)](https://www.chedong.com/phpMan.php/man/cachemetadatasize/8/markdown)                 System Manager's Manual                [_cache_metadata_size_(8)](https://www.chedong.com/phpMan.php/man/cachemetadatasize/8/markdown)

## NAME
       **cache_metadata_size  **- Estimate the size of the metadata device needed for a given configura‐
       tion.

## SYNOPSIS
       **cache_metadata_size **[_options_]

## DESCRIPTION
### cache_metadata_size estimates the size of the metadata.
              Either **--nr-blocks**, or **--block-size **and **--device-size **must be specified.

## OPTIONS
### --nr-blocks {natural}
              Specify the number of cache blocks.

### --block-size {sectors}
              Specify the size of each cache block in 512 byte sectors.

### --device-size {sectors}
              Specify total size of the fast device used in the cache.  In 512 byte sectors.

### --max-hint-width {nr bytes}
              Specify hint width.

           Cache policies use a per block 'hint' to record extra info (for instance
           hit counts).  At the moment all policies use a 4 byte hint
           width.  If you want to use a different hint width specify it with this
           switch.


## EXAMPLE
       $ **cache_metadata_size --nr-blocks **10240

       $ **cache_metadata_size --block-size **128 **--device-size **1024000

## SEE ALSO
       [**cache_dump**(8)](https://www.chedong.com/phpMan.php/man/cachedump/8/markdown), [**cache_repair**(8)](https://www.chedong.com/phpMan.php/man/cacherepair/8/markdown), [**cache_restore**(8)](https://www.chedong.com/phpMan.php/man/cacherestore/8/markdown)

## AUTHOR
       Joe Thornber <<ejt@redhat.com>>, Heinz Mauelshagen <<heinzm@redhat.com>>

System Manager's Manual                  Device Mapper Tools                  [_cache_metadata_size_(8)](https://www.chedong.com/phpMan.php/man/cachemetadatasize/8/markdown)