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From: Oliver Martin <oliver@volatilevoid.net>
To: linux-raid@vger.kernel.org
Subject: Creating a 3-disk RAID6 array
Date: Thu, 17 May 2012 03:24:26 +0200	[thread overview]
Message-ID: <4FB4534A.5070608@volatilevoid.net> (raw)

Hi,

is there any specific reason why md refuses to create a RAID6 array with 
3 disks? My (probably naive) understanding suggests it should be the 
same as a 3-disk RAID1, similar to a 2-disk RAID5.

The reason I'm asking is that I currently have space on three disks for 
a new array, and would like to expand it when I add a fourth. I tried 
this scenario with a few loopback devices, but the only way to go from a 
3-disk RAID1 to a 4-disk RAID6 seems to be via an intermediate 3-disk 
RAID5, requiring two reshapes. I'd like to avoid one of them, if at all 
possible.

Regards,
Oliver

             reply	other threads:[~2012-05-17  1:24 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-17  1:24 Oliver Martin [this message]
2012-05-17  1:38 ` Creating a 3-disk RAID6 array NeilBrown
2012-05-17 13:18   ` David Brown
2012-05-17 14:04     ` John Robinson
2012-05-18  7:24       ` David Brown
2012-05-18  7:30       ` H. Peter Anvin
2012-05-18  7:57         ` NeilBrown
2012-05-19  0:04           ` H. Peter Anvin
2012-05-17 21:02   ` Dan Williams
2012-05-17 23:27     ` Oliver Martin
2012-05-17  4:22 ` Bill Davidsen
2012-05-18  2:36 ` Stan Hoeppner

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