|| ||Neil Brown <firstname.lastname@example.org>|
|| ||ANNOUNCE: mdadm 2.6 - A tool for managing Soft RAID under Linux|
|| ||Thu, 21 Dec 2006 17:27:42 +1100|
I am pleased to announce the availability of
mdadm version 2.6
It is available at the usual places:
and via git at
mdadm is a tool for creating, managing and monitoring
device arrays using the "md" driver in Linux, also
known as Software RAID arrays.
Release 2.6 adds assorted fixes and improvements and a new major mode.
"Incremental Assembly" via -I or --incremental can be used to
assemble an array one device at a time. The idea is that you get
udev to run "mdadm -Iq devicename" on each new block device that it
finds. Anything that is part of an array gets included in an array as
Two special notes:
1/ This is very new code and is probably buggy. It passes a few basic
tests, and helped me find some kernel bugs, but it is still fresh
and should not be considered 'stable'. Please test and provide
2/ There is a bug in the linux kernel that makes incremental assembly
not possible in general (you cannot safely remove a drive from an array
that has not yet been started. This is needed if an old device was
detected first). If mdadm detects a kernel which might have the
bug, it rejects --incremental requests.
The bug will hopefully be fixed in 2.6.20 and this mdadm release
contains patches for 2.6.18, 126.96.36.199 and 2.6.19. Apply the
appropriate patch to test --incremental.
- Fixed UUID printing in "--detail --brief" for version1 metadata.
- --update=resync did exactly the wrong thing for version1 metadata.
It caused a resync to not happen, rather than to happen.
- Allow --assemble --force to mark a raid6 clean when it has two
missing devices (which is needed else if won't assemble.
Without this fix it would only assemble if one or zero
- Support --update=devicesize for cases where the underlying device
can change size.
- Default to --auto=yes so the array devices with 'standard' names
get created automatically, as this is almost always what is wanted.
- Give useful message if raid4/5/6 cannot be started because it is
not clean and is also degraded.
- Increase raid456 stripe cache size if needed to --grow the array.
The setting used unfortunately requires intimate knowledge of the
kernel, and it not reset when the reshape finishes.
- Change 'Device Size' to 'Used Dev Size' because it only shows how
much of each device is actually used, not how big they are.
- --wait or -W will wait for resync activity to finish on the given
- Fix some problems with --update=uuid and add a test.
- If two drives in a raid5 disappear at the same time, then "-Af"
will add them both in rather than just one and forcing the array
to 'clean'. This is slightly safer in some cases.
- Check device is large enough before hot-add: this improves quality
of error message.
- Don't hold md device open for so long in --monitor mode - map_dev
can be slow and interferes with trying to stop the array.
- Support --uuid= with --create to choose your own UUID.
- New major more "--incremental" for incremental assemble of arrays,
intended for use with udev.
Development of mdadm is sponsored by
SUSE Labs, Novell Inc.
NeilBrown 21st December 2006
Blessed Christmas to all.
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to email@example.com
More majordomo info at http://vger.kernel.org/majordomo-info.html