I am pleased to announce the availability of
mdadm version 3.2.1
It is available at the usual places:
and via git at
Many of the changes in this release are of internal interest only,
restructuring and refactoring code and so forth.
Most of the bugs found and fixed during development for 3.2.1 have been
back-ported for the recently-release 3.1.5 so this release primarily
provides a few new features over 3.1.5.
- policy framework
Policy can be expressed for moving spare devices between arrays, and
for how to handle hot-plugged devices. This policy can be different
for devices plugged in to different controllers etc.
This, for example, allows a configuration where when a device is plugged
in it is immediately included in an md array as a hot spare and
possibly starts recovery immediately if an array is degraded.
- some understanding of mbr and gpt paritition tables
This is primarly to support the new hot-plug support. If a
device is plugged in and policy suggests it should have a partition table,
the partition table will be copied from a suitably similar device, and
then the partitions will hot-plug and can then be added to md arrays.
- "--incremental --remove" can remember where a device was removed from
so if a device gets plugged back in the same place, special policy applies
to it, allowing it to be included in an array even if a general hotplug
will not be included.
- enhanced reshape options, including growing a RAID0 by converting to RAID4,
restriping, and converting back. Also convertions between RAID0 and
RAID10 and between RAID1 and RAID10 are possible (with a suitably recent
- spare migration for IMSM arrays.
Spare migration can now work across 'containers' using non-native metadata
and specifically Intel's IMSM arrays support spare migrations.
- OLCE and level migration for Intel IMSM arrays.
OnLine Capacity Expansion and level migration (e.g. RAID0 -> RAID5) is
supported for Intel Matrix Storage Manager arrays.
This support is currently 'experimental' for technical reasons. It can
be enabled with "export MDADM_EXPERIMENTAL=1"
- avoid including wayward devices
If you split a RAID1, mount the two halves as two separate degraded RAID1s,
and then later bring the two back together, it is possible that the md
metadata won't properly show that one must over-ride the other.
mdadm now does extra checking to detect this possibilty and avoid
potentially corrupting data.
- remove any possible confusion between similar options.
e.g. --brief and --bitmap were mapped to 'b' and mdadm wouldn't
notice if one was used where the other was expected.
- allow K,M,G suffixes on chunk sizes
While mdadm-3.2.1 is considered to be reasonably stable, you should
only use it if you want to try out the new features, or if you
generally like to be on the bleeding edge. If the new features are not
important to you, then 3.1.5 is probably the appropriate version to be using
until 3.2.2 comes out.
NeilBrown 28th March 2011