--- /dev/null
+Subject: ANNOUNCE: mdadm 3.3 - A tools for managing md Soft RAID under Linux
+
+I am pleased to announce the availability of
+ mdadm version 3.3
+
+It is available at the usual places:
+ http://www.kernel.org/pub/linux/utils/raid/mdadm/
+and via git at
+ git://github.com/neilbrown/mdadm
+ git://neil.brown.name/mdadm
+ http://git.neil.brown.name/git/mdadm
+
+This is a major new release so don't be too surprised if there are a
+few issues. If I hear about them they will be fixed in 3.3.1.
+git log reports nearly 500 changes since 3.2.6 so I won't list them
+all.
+
+Some highlights are:
+
+- Some array reshapes can proceed without needing backup file.
+ This is done by changing the 'data_offset' so we never need to write
+ any data back over where it was before. If there is no "head space"
+ or "tail space" to allow data_offset to change, the old mechanism
+ with a backup file can still be used.
+- RAID10 arrays can be reshaped to change the number of devices,
+ change the chunk size, or change the layout between 'near'
+ and 'offset'.
+ This will always change data_offset, and will fail if there is no
+ room for data_offset to be moved.
+- "--assemble --update=metadata" can convert a 0.90 array to a 1.0 array.
+- bad-block-logs are supported (but not heavily tested yet)
+- "--assemble --update=revert-reshape" can be used to undo a reshape
+ that has just been started but isn't really wanted. This is very
+ new and while it passes basic tests it cannot be guaranteed.
+- improved locking between --incremental and --assemble
+- uses systemd to run "mdmon" if systemd is configured to do that.
+- kernel names of md devices can be non-numeric. e.g. "md_home" rather than
+ "md0". This will probably confuse lots of other tools, so you need to
+ echo CREATE names=yes >> /etc/mdadm.conf
+ or the feature will not be used. (you also need a reasonably new kernel).
+- "--stop" can be given a kernel name instead of a device name. i.e
+ mdadm --stop md4
+ will work even if /dev/md4 doesn't exist.
+- "--detail --export" has some information about the devices in the array
+- --dump and --restore can be used to backup and restore the metadata on an
+ array.
+- Hot-replace is supported with
+ mdadm /dev/mdX --replace /dev/foo
+ and
+ mdadm /dev/mdX --replace /dev/foo --with /dev/bar
+- Config file can be a directory in which case all "*.conf" files are
+ read in lexical order.
+ Default is to read /etc/mdadm.conf and then /etc/mdadm.conf.d
+ Thus
+ echo CREATE name=yes > /etc/mdadm.conf.d/names.conf
+ will also enable the use of named md devices.
+
+- Lots of improvements to DDF support including adding support for
+ RAID10 (thanks Martin Wilck).
+
+and lots of bugfixes and other little changes.
+
+NeilBrown 3rd September 2013
Please see git logs for detailed change log.
This file just contains highlight.
+Changes Prior to release 3.3
+- Some array reshapes can proceed without needing backup file.
+ This is done by changing the 'data_offset' so we never need to write
+ any data back over where it was before. If there is no "head space"
+ or "tail space" to allow data_offset to change, the old mechanism
+ with a backup file can still be used.
+- RAID10 arrays can be reshaped to change the number of devices,
+ change the chunk size, or change the layout between 'near'
+ and 'offset'.
+ This will always change data_offset, and will fail if there is no
+ room for data_offset to be moved.
+- "--assemble --update=metadata" can convert a 0.90 array to a 1.0 array.
+- bad-block-logs are supported (but not heavily tested yet)
+- "--assemble --update=revert-reshape" can be used to undo a reshape
+ that has just been started but isn't really wanted. This is very
+ new and while it passes basic tests it cannot be guaranteed.
+- improved locking between --incremental and --assemble
+- uses systemd to run "mdmon" if systemd is configured to do that.
+- kernel names of md devices can be non-numeric. e.g. "md_home" rather than
+ "md0". This will probably confuse lots of other tools, so you need to
+ echo CREATE names=yes >> /etc/mdadm.conf
+ or the feature will not be used. (you also need a reasonably new kernel).
+- "--stop" can be given a kernel name instead of a device name. i.e
+ mdadm --stop md4
+ will work even if /dev/md4 doesn't exist.
+- "--detail --export" has some information about the devices in the array
+- --dump and --restore can be used to backup and restore the metadata on an
+ array.
+- Hot-replace is supported with
+ mdadm /dev/mdX --replace /dev/foo
+ and
+ mdadm /dev/mdX --replace /dev/foo --with /dev/bar
+- Config file can be a directory in which case all "*.conf" files are
+ read in lexical order.
+ Default is to read /etc/mdadm.conf and then /etc/mdadm.conf.d
+ Thus
+ echo CREATE name=yes > /etc/mdadm.conf.d/names.conf
+ will also enable the use of named md devices.
+
+- Lots of improvements to DDF support including adding support for
+ RAID10 (thanks Martin Wilck).
+
+Changes Prior to release 3.2.6
+ - There are no real stand-out fixes, just lots of little bits and pieces.
+
+Changes Prior to release 3.2.5
+ - This release primarily fixes a serious regression in 3.2.4.
+ This regression does *not* cause any risk to data. It simply
+ means that adding a device with "--add" would sometime fail
+ when it should not.
+
+ - The fix also includes a couple of minor fixes such as making
+ the "--layout=preserve" option to "--grow" work again.
+
+
+Changes Prior to release 3.2.4
+"--oneline" log of changes is below. Some notable ones are:
+
+ - --offroot argument to improve interactions between mdmon and initrd
+ - --prefer argument to select which /dev names to display in some
+ circumstances.
+ - relax restructions on when "--add" will be allowed
+ - Fix bug with adding write-intent-bitmap to active array
+ - Now defaults to "/run/mdadm" for storing run-time files.
+
+Changes Prior to release 3.2.3
+ - The largest single area of change is support for reshape of Intel
+ IMSM arrays (OnLine Capacity Explansion and Level Migration).
+ - Among other fixes, this now has a better chance of surviving if a
+ device fails during reshape.
+
+Changes Prior to release 3.2.2
+ - reshaping IMSM (Intel metadata) arrays is no longer 'experimental',
+ it should work properly and be largely compatible with IMSM drivers in
+ other platforms.
+ - --assume-clean can be used with --grow --size to avoid resyncing the
+ new part of the array. This is only support with very new kernels.
+ - RAID0 arrays can have chunksize which is not a power of 2. This has been
+ supported in the kernel for a while but is only now supprted by
+ mdadm.
+
+ - A new tool 'raid6check' is available which can check a RAID6 array,
+ or part of it, and report which device is most inconsistent with the
+ others if any stripe is inconsistent. This is still under development
+ and does not have a man page yet. If anyone tries it out and has any
+ questions or experience to report, they would be most welcome on
+ linux-raid@vger.kernel.org.
+
+Changes Prior to release 3.2.1
+ - 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
+ kernel).
+
+ - 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
+
+Changes Prior to release 3.2
+ - By far the most significant change in this release related to the
+ management of reshaping arrays. This code has been substantially
+ re-written so that it can work with 'externally managed metadata' -
+ Intel's IMSM in particular. We now support level migration and
+ OnLine Capacity Expansion on these arrays.
+ - Policy framework.
+ Various policy statements can be made in the mdadm.conf to guide
+ the behaviour of mdadm, particular with regards to how new devices
+ are treated by "mdadm -I".
+ Depending on the 'action' associated with a device (identified by
+ its 'path') such need devices can be automatically re-added to and
+ existing array that they previously fell out off, or automatically
+ added as a spare if they appear to contain no data.
+
+ - mdadm now has a limited understanding of partition tables. This
+ allows the policy framework to make decisions about partitioned
+ devices as well.
+
+ - --incremental --remove can be told what --path the device was on,
+ and this info will be recorded so that another device appearing at
+ the same physical location can be preferentially added to the same
+ array (provides the spare-same-slot action policy applied to the
+ path).
+
+ - A new flags "--invalid-backup" flag is available in --assemble
+ mode. This can be used to re-assemble an array which was stopping
+ in the middle of a reshape, and for which the 'backup file' is no
+ longer available or is corrupted. The array may have some
+ corruption in it at the point where reshape was up to, but at least
+ the rest of the array will become available.
+
+
+ - Various internal restructuring - more is needed.
+
+Changes Prior to release 3.1.5
+ - Fixes for v1.x metadata on big-endian machines.
+ - man page improvements
+ - Improve '--detail --export' when run on partitions of an md array.
+ - Fix regression with removing 'failed' or 'detached' devices.
+ - Fixes for "--assemble --force" in various unusual cases.
+ - Allow '-Y' to mean --export. This was documented but not implemented.
+ - Various fixed for handling 'ddf' metadata. This is now more reliable
+ but could benefit from more interoperability testing.
+ - Correctly list subarrays of a container in "--detail" output.
+ - Improve checks on whether the requested number of devices is supported
+ by the metadata - both for --create and --grow.
+ - Don't remove partitions from a device that is being included in an
+ array until we are fully committed to including it.
+ - Allow "--assemble --update=no-bitmap" so an array with a corrupt
+ bitmap can still be assembled.
+ - Don't allow --add to succeed if it looks like a "--re-add" is probably
+ wanted, but cannot succeed. This avoids inadvertently turning
+ devices into spares when an array is failed.
+
Changes Prior to release 3.1.4
Two fixes related to configs that aren't using udev:
- Don't remove md devices which 'standard' names on --stop
- Allow --incremental to add spares to an array
- Accept --no-degraded as a deprecated option rather than
throwing an error
- - Return correct success status when --incrmental assembling
+ - Return correct success status when --incrmental assembling
a container which does not yet have enough devices.
- Don't link mdadm with pthreads, only mdmon needs it.
- Fix compiler warning due to bad use of snprintf
Changes Prior to release 3.1.2
- The default metadata has change again (sorry about that).
It is now v1.2 and will hopefully stay that way. It turned
- out there with boot-block issues with v1.1 which make it
+ out there with boot-block issues with v1.1 which make it
unsuitable for a default, though in many cases it is still
suitable to use.
- Stopping a container is not permitted when members are still
- Add section on 'scrubbing' to 'md' man page.
- Various command-line-option parsing improvements.
- ... and lots of other bug fixes.
-
+
Changes Prior to release 3.1.1
- Multiple fixes for new --grow levels including fixes for
serious data corruption problems.
- Support --grow to change level from RAID1 -> RAID5 -> RAID6 and
back.
- Support --grow to reduce the number of devices in RAID4/5/6.
- - Support restart of these grow options which assembling an array
+ - Support restart of these grow options which assembling an array
which is partially grown.
- Assorted tests of this code, and of different RAID6 layouts.
-
+
Changes Prior to release 3.0.3
- Improvements for creating arrays giving just a name, like 'foo',
rather than the full '/dev/md/foo'.
- Handle merging of devices that have left an IMSM array and are
being re-incorporated.
- Add missing space in "--detail --brief" output.
-
+
Changes Prior to release 3.0.2
- Fix crash when hosthost is not set, as often happens in
early boot.
- Fix various segfaults
- Fixed for --examine with containers
- Lots of other little fixes.
-
+
Changes Prior to release 3.0
- Support for externally managed metadata, specifically DDF and IMSM.
- Depend on udev to create entries in /dev, rather than creating them
projects / thirdparty / mdadm.git / commitdiff
