ANNOUNCE-2.6

   1 Subject:  ANNOUNCE: mdadm 2.6 - A tool for managing Soft RAID under Linux
   2
   3 I am pleased to announce the availability of
   4    mdadm version 2.6
   5
   6 It is available at the usual places:
   7    http://www.cse.unsw.edu.au/~neilb/source/mdadm/
   8 and
   9    countrycode=xx.
  10    http://www.${countrycode}kernel.org/pub/linux/utils/raid/mdadm/
  11 and via git at
  12    git://neil.brown.name/mdadm
  13    http://neil.brown.name/git?p=mdadm
  14
  15 mdadm is a tool for creating, managing and monitoring
  16 device arrays using the "md" driver in Linux, also
  17 known as Software RAID arrays.
  18
  19 Release 2.6 adds assorted fixes and improvements and a new major mode.
  20 "Incremental Assembly"  via -I or --incremental can be used to
  21 assemble an array one device at a time.  The idea is that you get
  22 udev to run  "mdadm -Iq devicename" on each new block device that it
  23 finds.  Anything that is part of an array gets included in an array as
  24 appropriate.
  25 Two special notes:
  26  1/ This is very new code and is probably buggy.  It passes a few basic
  27     tests, and helped me find some kernel bugs, but it is still fresh
  28     and should not be considered 'stable'.  Please test and provide
  29     feedback.
  30  2/ There is a bug in the linux kernel that makes incremental assembly
  31     not possible in general (you cannot safely remove a drive from an array
  32     that has not yet been started. This is needed if an old device was
  33     detected first).  If mdadm detects a kernel which might have the
  34     bug, it rejects --incremental requests.
  35     The bug will hopefully be fixed in 2.6.20 and this mdadm release
  36     contains patches for 2.6.18, 2.6.18.6 and 2.6.19.  Apply the
  37     appropriate patch to test --incremental.
  38
  39 Changelog Entries:
  40     -   Fixed UUID printing in "--detail --brief" for version1 metadata.
  41     -   --update=resync did exactly the wrong thing for version1 metadata.
  42         It caused a resync to not happen, rather than to happen.
  43     -   Allow --assemble --force to mark a raid6 clean when it has two
  44         missing devices (which is needed else if won't assemble.
  45         Without this fix it would only assemble if one or zero
  46         missing devices.
  47     -   Support --update=devicesize for cases where the underlying device
  48         can change size.
  49     -   Default to --auto=yes so the array devices with 'standard' names
  50         get created automatically, as this is almost always what is wanted.
  51     -   Give useful message if raid4/5/6 cannot be started because it is
  52         not clean and is also degraded.
  53     -   Increase raid456 stripe cache size if needed to --grow the array.
  54         The setting used unfortunately requires intimate knowledge of the
  55         kernel, and it not reset when the reshape finishes.
  56     -   Change 'Device Size' to 'Used Dev Size' because it only shows how
  57         much of each device is actually used, not how big they are.
  58     -   --wait or -W will wait for resync activity to finish on the given
  59         devices.
  60     -   Fix some problems with --update=uuid and add a test.
  61     -   If two drives in a raid5 disappear at the same time, then "-Af"
  62         will add them both in rather than just one and forcing the array
  63         to 'clean'.  This is slightly safer in some cases.
  64     -   Check device is large enough before hot-add: this improves quality
  65         of error message.
  66     -   Don't hold md device open for so long in --monitor mode - map_dev
  67         can be slow and interferes with trying to stop the array.
  68     -   Support --uuid= with --create to choose your own UUID.
  69     -   New major more "--incremental" for incremental assemble of arrays,
  70         intended for use with udev.
  71
  72 Development of mdadm is sponsored by
  73  SUSE Labs, Novell Inc.
  74
  75 NeilBrown  21st December 2006
  76 Blessed Christmas to all.