управлять MD-устройствами, также известными как Linux Software RAID (manage MD devices aka Linux Software RAID)
MANAGE MODE
Usage: mdadm device options... devices...
This usage will allow individual devices in an array to be
failed, removed or added. It is possible to perform multiple
operations with on command. For example:
mdadm /dev/md0 -f /dev/hda1 -r /dev/hda1 -a /dev/hda1
will firstly mark /dev/hda1 as faulty in /dev/md0 and will then
remove it from the array and finally add it back in as a spare.
However only one md array can be affected by a single command.
When a device is added to an active array, mdadm checks to see if
it has metadata on it which suggests that it was recently a
member of the array. If it does, it tries to "re-add" the
device. If there have been no changes since the device was
removed, or if the array has a write-intent bitmap which has
recorded whatever changes there were, then the device will
immediately become a full member of the array and those
differences recorded in the bitmap will be resolved.
