---
name: "mdtab"
section: "5"
platform: "linux"
package: "raidtools"
version: "0.42-33"
release: "Debian 3.0 (Woody)"
platforms: ["linux"]
url: "https://new.carta.tech/mdtab"
---

# mdtab(5)

configuration file for md devices

## NAME

mdtab - configuration file for md devices

## DESCRIPTION

**/etc/mdtab** is a configuration file for the md tools (**mdadd** and co). Its goal is to record a configuration for each md device the system should be configurated for.

## FORMAT

**/etc/mdtab** describe each md device, one per line, with the following syntax :

md\_dev		mode,c,f,crc32		dev1 dev2 ... devn

- *md\_dev*

  md device (e.g. /dev/md0),\

- *mode*

  one of **linear**, **raid0** or **raid1**,\

- *c*

  chunk factor (optional, not applicable to **linear** mode). Can also be set as **nk** where n is the chunk size in kilobytes,\

- *f*

  maximum fault number (optional, not applicable to **linear** nor **raid-0** mode),\

- *crc32*

  optional control informations added by mdcreate. This is checked by **mdadd** and co when using the md device.\

- *dev1 ...*

  real devices that are part of the md device.

  Each section is separated by spaces or tabs. Note that there are no spaces in the option field.

## FILES

**/etc/mdtab**

## SEE ALSO

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