[thirdparty/mdadm.git] / ANNOUNCE-3.3

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
Commit	Line	Data
6f02172d N	1	Subject: ANNOUNCE: mdadm 3.3 - A tools for managing md Soft RAID under Linux
	2
	3	I am pleased to announce the availability of
	4	mdadm version 3.3
	5
	6	It is available at the usual places:
	7	http://www.kernel.org/pub/linux/utils/raid/mdadm/
	8	and via git at
	9	git://github.com/neilbrown/mdadm
	10	git://neil.brown.name/mdadm
	11	http://git.neil.brown.name/git/mdadm
	12
	13	This is a major new release so don't be too surprised if there are a
	14	few issues. If I hear about them they will be fixed in 3.3.1.
	15	git log reports nearly 500 changes since 3.2.6 so I won't list them
	16	all.
	17
	18	Some highlights are:
	19
	20	- Some array reshapes can proceed without needing backup file.
	21	This is done by changing the 'data_offset' so we never need to write
	22	any data back over where it was before. If there is no "head space"
	23	or "tail space" to allow data_offset to change, the old mechanism
	24	with a backup file can still be used.
	25	- RAID10 arrays can be reshaped to change the number of devices,
	26	change the chunk size, or change the layout between 'near'
	27	and 'offset'.
	28	This will always change data_offset, and will fail if there is no
	29	room for data_offset to be moved.
	30	- "--assemble --update=metadata" can convert a 0.90 array to a 1.0 array.
	31	- bad-block-logs are supported (but not heavily tested yet)
	32	- "--assemble --update=revert-reshape" can be used to undo a reshape
	33	that has just been started but isn't really wanted. This is very
	34	new and while it passes basic tests it cannot be guaranteed.
	35	- improved locking between --incremental and --assemble
	36	- uses systemd to run "mdmon" if systemd is configured to do that.
	37	- kernel names of md devices can be non-numeric. e.g. "md_home" rather than
	38	"md0". This will probably confuse lots of other tools, so you need to
	39	echo CREATE names=yes >> /etc/mdadm.conf
	40	or the feature will not be used. (you also need a reasonably new kernel).
	41	- "--stop" can be given a kernel name instead of a device name. i.e
	42	mdadm --stop md4
	43	will work even if /dev/md4 doesn't exist.
	44	- "--detail --export" has some information about the devices in the array
	45	- --dump and --restore can be used to backup and restore the metadata on an
	46	array.
	47	- Hot-replace is supported with
	48	mdadm /dev/mdX --replace /dev/foo
	49	and
	50	mdadm /dev/mdX --replace /dev/foo --with /dev/bar
	51	- Config file can be a directory in which case all "*.conf" files are
	52	read in lexical order.
	53	Default is to read /etc/mdadm.conf and then /etc/mdadm.conf.d
	54	Thus
	55	echo CREATE name=yes > /etc/mdadm.conf.d/names.conf
	56	will also enable the use of named md devices.
	57
	58	- Lots of improvements to DDF support including adding support for
	59	RAID10 (thanks Martin Wilck).
	60
	61	and lots of bugfixes and other little changes.
	62
	63	NeilBrown 3rd September 2013