Re: md: Can't convert raid level

From: Neil Brown
Date: Wed May 13 2009 - 06:39:20 EST


On Wednesday May 13, roma1390@xxxxxxxxx wrote:
> Hello,
>
> tested with linux-2.6.git a4f1cb9f3c42e5d278b0678ed5225d9331a8dcff
>
> If i have spare disk i can grow
> raid1, raid4, raid5 and raid6
>
> but can't convert to other raid level. Raid conversation matrix:
>
> from\to | 0 | 1 | 4 | 5 | 6
> ============================
> raid0 | - - - - -
> raid1 | - + - - -
> raid4 |-22 -22 + -22 -22
> raid5 |-22 -22 -22 + -22
> raid6 |-22 -22 -22 -22 +
>
> Sample test script, log, dmesg, kernel config is attached.
>
> Major problem is than can not do online covert from raid5 to raid6:

Correct. This functionality has not been implemented yet.

The kernel contains the required support, but mdadm does not make use
of it correctly yet.

NeilBrown
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