ANNOUNCE: mdadm 2.4 - A tool for managing Soft RAID under Linux

ANNOUNCE: mdadm 2.4 - A tool for managing Soft RAID under Linux

[Neil Brown]

I am pleased to announce the availability of
   mdadm version 2.4

It is available at the usual places:
   http://www.cse.unsw.edu.au/~neilb/source/mdadm/
and
   http://www.{countrycode}.kernel.org/pub/linux/utils/raid/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 2.4 primarily adds support for increasing the number of
devices in a RAID5 array, which requires 2.6.17 (or some -rc or -mm
prerelease).
It also includes a number of minor functionality enhancements and
documentation updates.

Changelog Entries:
    -   Rewrite 'reshape' support including performing a backup
	of the critical region for a raid5 growth, and restoring that
	backup after a crash.
    -   Put a 'canary' at each end of the backup so a corruption
	can be more easily detected.
    -   Remove useless 'ident' arguement from ->getinfo_super method.
    -   Support --backup-file for backing-up critical section during
        growth.
    -   Erase old superblocks (of different versions) when creating new
        array.
    -   Allow --monitor to work with arrays with >28 devices
    -   Report reshape information in --detail
    -   Handle symlinks in /dev better
    -   Fix mess in --detail output which a device is missing.
    -   Manpage tidyup
    -   Support 'bitmap=' in mdadm.conf for auto-assembling arrays with
	write-intent bitmaps in separate files.
    -   Updates to md.4 man page including section on RESTRIPING and SYSFS

Development of mdadm is sponsored by
 SUSE Labs, Novell Inc.

NeilBrown  30th March 2006

Re: ANNOUNCE: mdadm 2.4 - A tool for managing Soft RAID under Linux

[Farkas Levente]

Neil Brown wrote:
> I am pleased to announce the availability of
>    mdadm version 2.4
> 
> It is available at the usual places:
>    http://www.cse.unsw.edu.au/~neilb/source/mdadm/
> and
>    http://www.{countrycode}.kernel.org/pub/linux/utils/raid/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 2.4 primarily adds support for increasing the number of
> devices in a RAID5 array, which requires 2.6.17 (or some -rc or -mm
> prerelease).

that's realy a long avaiting feature. but at the same time wouldn't it 
be finally possible to convert a non raid partition to an raid1? it's 
avery common thing and they used to said it's even working on windows:-(

just my 2c.

-- 
   Levente                               "Si vis pacem para bellum!"

Re[2]: ANNOUNCE: mdadm 2.4 - A tool for managing Soft RAID under Linux

[Jim Klimov]

Hello Farkas,

FL> that's realy a long avaiting feature. but at the same time wouldn't it
FL> be finally possible to convert a non raid partition to an raid1? it's
FL> avery common thing and they used to said it's even working on windows:-(
That would be cooler than making a metadevice and copying tons of
files :)

However, AFAIK this would require some support on FS side as well?
FS-addressable space in a RAID metadevice (i.e. submirror) is aligned
till the pre-last 64K block. If the partition was used up completely,
the last [64..128]Kb can be used by its data and need to be remapped
to a free location. And this is quite FS-dependant (like grow/shrink)
and should be addressed by those FS toolkits.

tune2fs and e2fsck do some similar remapping job when we enable/disable
spare superblocks on a used filesystem...

-- 
Best regards,
 Jim Klimov                            mailto:klimov@2ka.mipt.ru

Re: ANNOUNCE: mdadm 2.4 - A tool for managing Soft RAID under Linux

[Maurice Hilarius]

Neil Brown wrote:
> I am pleased to announce the availability of
>    mdadm version 2.4
> ..
>
> Release 2.4 primarily adds support for increasing the number of
> devices in a RAID5 array, which requires 2.6.17 (or some -rc or -mm
> prerelease).
> ..
Is there a corresponding means to increase the size of a file system to
use this?
>     -   Allow --monitor to work with arrays with >28 devices
>   
So, how DO we get past the old 26 device "alphabet limit" ?

Thanks, as always, for the great work, Neil.



-- 

With our best regards,


Maurice W. Hilarius        Telephone: 01-780-456-9771
Hard Data Ltd.  FAX:       01-780-456-9772
11060 - 166 Avenue         email:maurice@harddata.com
Edmonton, AB, Canada       http://www.harddata.com/
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