---
name: "writeboosttab"
section: "5"
platform: "linux"
package: "writeboost"
version: "1.20170616-1.3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/writeboosttab"
---

# writeboosttab(5)

mappings of cache(d) devices

## NAME

writeboosttab - mappings of cache(d) devices

## SYNOPSIS

**/etc/writeboosttab**

## DESCRIPTION

The file **writeboosttab** contains information about mappings between caching and cached block devices for writeboost utility.

Each mapping is described on a separate line; Empty lines and lines starting with '#' are ignored; Fields on each line are separated by tabs or spaces;

**The first field** (*dm\_name*)

This field describes the name of device-mapepr block device that will be created as result of mapping.

Typically after successful mapping the *dm\_name* will appear in the */dev/mapper* folder.

**The second field** (*hdd\_device*)

This field describes path to the cached block device, typically "slow" (rotational) HDD.

**The third field** (*ssd\_device*).

This field describes path to the caching block device, typically "fast" SSD.

**The forth field** (*options*)

This optional field describes comma-separated list of options passed to dm-writeboost.

It is recommended to use reliable paths to block devices like */dev/disk/by-uuid/{UUID}* or similar.

## EXAMPLES

The following is an example of an entry in the **/etc/writeboosttab** file:

```
 cached_hdd  /dev/disk/by-uuid/2e8260bc-024c-4252-a695-a73898c974c7  /dev/disk/by-partuuid/43372b68-3407-45fa-9b2f-61afe9c26a68  writeback_threshold=70,sync_data_interval=3600
```

## FILES

*/etc/writeboosttab*

## SEE ALSO

[**writeboost**(8)](/writeboost/8.md)

## AUTHOR

 Dmitry Smirnov \<onlyjob@member.fsf.org\>

## COPYRIGHT

 Copyright 2015-2017 Libre Solutions Pty Ltd (http://raid6.com.au)

## LICENSE

 This program is free software: you can redistribute it and/or modify\
  it under the terms of the GNU General Public License as published by\
  the Free Software Foundation, either version 2 of the License, or\
  (at your option) any later version.

 This package is distributed in the hope that it will be useful,\
  but WITHOUT ANY WARRANTY; without even the implied warranty of\
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\
  GNU General Public License for more details.

 You should have received a copy of the GNU General Public License\
  along with this program. If not, see \<http://www.gnu.org/licenses/\>.