Subject: ANNOUNCE: mdadm 2.6 - A tool for managing Soft RAID under Linux I am pleased to announce the availability of mdadm version 2.6 It is available at the usual places: http://www.cse.unsw.edu.au/~neilb/source/mdadm/ and countrycode=xx. http://www.${countrycode}kernel.org/pub/linux/utils/raid/mdadm/ and via git at git://neil.brown.name/mdadm http://neil.brown.name/git?p=mdadm 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 appropriate. 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 feedback. 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, 2.6.18.6 and 2.6.19. Apply the appropriate patch to test --incremental. Changelog Entries: - 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 missing devices. - 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 devices. - 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.