mdadd(8)

NAME
mdadd, mdrun, mdstop, mdop - command set to manage md devices.

SYNOPSIS
mdadd [options] [md_device] [block_device_1 block_device_2 ...] mdrun [options] md_device mdstop [options] md_device mdop [options] md_device block_device

DESCRIPTION
Md devices are virtual devices used to group real block devices. This way, two 100MB disks can be used as a single 200MB disk, whatever their interface type. If you're using the /proc filesystem, /proc/mdstat gives you informations about md devices status. Avaible commands are :
mdadd : groups several real devices into a virtual one.
mdrun : set a virtual device as usable, with a given mode.
mdstop : free real devices belonging to a virtual one, and flush buffers.
mdop : invalidate or revalidate a device belonging to a raid-1 device

OPTIONS

-a  Apply the command to the set of devices described in /etc/mdtab.

-r  Starts the virtual device after the real devices are being added. Only applicable to mdadd.

-px where x is :
    l : starts the device in linear mode,
    0 : starts the device in raid-0 mode,
    1 : starts the device in raid-1 mode.
    assuming that the mode is either compiled into the kernel or loaded using the insmod program. Only applicable to mdrun.

-cn (raid-0 and raid-1 only)
    Set the chunk size as PAGE_SIZE << n. You can also set the chunk size in kilobytes with -cxk where x is a power of 2. Only applicable to mdrun.

-fn (raid-1 only)
    Set the maximum fault number as n. Only applicable to mdrun.

-i  (raid1 only)
    Invalidate a physical device belonging to a raid-1 device. Only applicable to mdop.

-v  (raid1 only)
    Revalidate an invalidated physical device belonging to a raid-1 device. Only applicable to mdop.

-V  Show version number as well as driver version the command is compiled for.

EXAMPLES
To configure the device : /sbin/mdadd /dev/md0 /dev/sdb1 /dev/sdc2 Warning, /sbin/mdadd /dev/md0 /dev/sdb1 /dev/sdc2 is different from /sbin/mdadd /dev/md0 /dev/sdc2 /dev/sdb1 because there's no internal ordering. To make it usable in linear mode : /sbin/mdrun -pl /dev/md0 To make it usable in striped mode, with 8kb chunks : /sbin/mdrun -p0 -c8k /dev/md0 To stop it : /sbin/mdstop /dev/md0 If you have described you md-devices in /etc/mdtab , you can replace the two first steps with /sbin/mdadd -ar

FILES
/sbin/mdadd : main command. Other commands are symlinks to this file.
/etc/mdtab : configuration file.
/proc/mdstat : driver and devices status

AUTHOR
mdadd was written as a kernel interface to md driver by Marc ZYNGIER <zyngier@amertume.ufr-info-p7.ibp.fr>.

BUGS
Options that are not applicable to a command are silently ignored and/or may lead to unxepected behaviour. This man page (and the whole documentation) is really brain-dead and should be rewritten. Any volunteer ?

SEE ALSO
mdtab(5)
modules package.
More informations in the README file included in the package.