Mailinglist Archive: opensuse (2576 mails)

[Manfred Hollstein <manfred@xxxxxxxxxxxxxxxxx>]

Hi David,

On Mon, 16 Feb 2009, 06:29:55 +0100, David C. Rankin wrote:
> [...]
> root@zion:/home/david # mdadm -Q -D /dev/md1
> /dev/md1:
>         Version : 01.00.03
>   Creation Time : Sun Jun 22 01:40:26 2008
>      Raid Level : raid1
>      Array Size : 467411004 (445.76 GiB 478.63 GB)
>   Used Dev Size : 934822008 (891.52 GiB 957.26 GB)
>    Raid Devices : 2
>   Total Devices : 2
> Preferred Minor : 1
>     Persistence : Superblock is persistent
>
>   Intent Bitmap : Internal
>   ^^^^^^^^^^^^^^^^^^^^^^^^
>     Update Time : Sun Feb 15 23:27:24 2009
>           State : active
>  Active Devices : 2
> Working Devices : 2
>  Failed Devices : 0
>   Spare Devices : 0
>
>            Name : 1
>            UUID : b119e184:e3bd8652:792c1ed2:3107e924
>          Events : 12
>
>     Number   Major   Minor   RaidDevice State
>        0       8       54        0      active sync   /dev/sdd6
>        1       8       38        1      active sync   /dev/sdc6
>
>
>       I'll go digest man mdadm a bit more. In the mean time, I there any 
> benefit to
> keeping it or removing it? I figure it is there for a reason, but what to you
> see in the real world.

It depends... I once had trouble because one disk repeatedly failed and
got kicked from the mirror; when I checked the disk it appeared OK, so I
re-added it to the mirror which resulted again in a full resync. I
eventually found out that it wasn't the disk, but the cables which
caused connectivity to be flaky. Bitmaps definitely help in keeping
synchronization times to a minimum. In my experience you don't need it
very often in your home environment - assuming you're using high quality
cables ;-) - while it's an absolute must-have e.g. in a cluster
environment where you must fail-over the mirror from time to time and
have to live with asynchronous drops between the storage elements.

FWIW, I have bitmaps enabled on all my systems.

HTH, cheers.

l8er
manfred
-- 
To unsubscribe, e-mail: opensuse+unsubscribe@xxxxxxxxxxxx
For additional commands, e-mail: opensuse+help@xxxxxxxxxxxx