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* Convert RAID5 to RAID6 in a live system
@ 2011-03-23  7:43 Stefan Roese
  2011-03-23  8:07 ` Mikael Abrahamsson
  0 siblings, 1 reply; 5+ messages in thread
From: Stefan Roese @ 2011-03-23  7:43 UTC (permalink / raw)
  To: linux-raid

Hi,

I'm currently in the process of converting a 3 disk RAID5 array into a 4 disk 
RAID5 array. I'm using mdadm 3.1.4 and Linux kernel 2.6.35-28-generic 
(Ubuntu). My questions now is this conversion save in a live (running) system? 
Or is this now allowed/supported?

Thanks.

Best regards,
Stefan

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Convert RAID5 to RAID6 in a live system
  2011-03-23  7:43 Convert RAID5 to RAID6 in a live system Stefan Roese
@ 2011-03-23  8:07 ` Mikael Abrahamsson
  2011-03-23  8:14   ` Roman Mamedov
  0 siblings, 1 reply; 5+ messages in thread
From: Mikael Abrahamsson @ 2011-03-23  8:07 UTC (permalink / raw)
  To: Stefan Roese; +Cc: linux-raid

On Wed, 23 Mar 2011, Stefan Roese wrote:

> I'm currently in the process of converting a 3 disk RAID5 array into a 4 disk
> RAID5 array. I'm using mdadm 3.1.4 and Linux kernel 2.6.35-28-generic
> (Ubuntu). My questions now is this conversion save in a live (running) system?
> Or is this now allowed/supported?

I guess you wanted to say "4 disk RAID6 array"?

In that case, yes, I have done it on 2.6.32 and mdadm version (something 
older) and it went just fine.

Neil wrote about it here <http://neil.brown.name/blog/20090817000931>.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Convert RAID5 to RAID6 in a live system
  2011-03-23  8:07 ` Mikael Abrahamsson
@ 2011-03-23  8:14   ` Roman Mamedov
  2011-03-23  9:07     ` Stefan Roese
  0 siblings, 1 reply; 5+ messages in thread
From: Roman Mamedov @ 2011-03-23  8:14 UTC (permalink / raw)
  To: Mikael Abrahamsson; +Cc: Stefan Roese, linux-raid

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On Wed, 23 Mar 2011 09:07:56 +0100 (CET)
Mikael Abrahamsson <swmike@swm.pp.se> wrote:

> On Wed, 23 Mar 2011, Stefan Roese wrote:
> 
> > I'm currently in the process of converting a 3 disk RAID5 array into a 4
> > disk RAID5 array. I'm using mdadm 3.1.4 and Linux kernel 2.6.35-28-generic
> > (Ubuntu). My questions now is this conversion save in a live (running)
> > system? Or is this now allowed/supported?
> 
> I guess you wanted to say "4 disk RAID6 array"?
> 
> In that case, yes, I have done it on 2.6.32 and mdadm version (something 
> older) and it went just fine.
> 
> Neil wrote about it here <http://neil.brown.name/blog/20090817000931>.

Additionally, I suggest that you also check "man mdadm" and note the
"--layout=preserve" option, if you use it, the RAID5 to RAID6 conversion while
adding one disk will happen instantly, without restriping (but only with a
resync of the new drive).

-- 
With respect,
Roman

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^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Convert RAID5 to RAID6 in a live system
  2011-03-23  8:14   ` Roman Mamedov
@ 2011-03-23  9:07     ` Stefan Roese
  2011-03-23 11:15       ` Mikael Abrahamsson
  0 siblings, 1 reply; 5+ messages in thread
From: Stefan Roese @ 2011-03-23  9:07 UTC (permalink / raw)
  To: Roman Mamedov; +Cc: Mikael Abrahamsson, linux-raid

On Wednesday 23 March 2011 09:14:24 Roman Mamedov wrote:
> > > I'm currently in the process of converting a 3 disk RAID5 array into a
> > > 4 disk RAID5 array. I'm using mdadm 3.1.4 and Linux kernel
> > > 2.6.35-28-generic (Ubuntu). My questions now is this conversion save
> > > in a live (running) system? Or is this now allowed/supported?
> > 
> > I guess you wanted to say "4 disk RAID6 array"?
> > 
> > In that case, yes, I have done it on 2.6.32 and mdadm version (something
> > older) and it went just fine.
> > 
> > Neil wrote about it here <http://neil.brown.name/blog/20090817000931>.
> 
> Additionally, I suggest that you also check "man mdadm" and note the
> "--layout=preserve" option, if you use it, the RAID5 to RAID6 conversion
> while adding one disk will happen instantly, without restriping (but only
> with a resync of the new drive).

Thanks. I already started with this conversion, so this "--layout=preserve" is 
not an option for me any more. But good to know that this conversion should 
work. But its slow - it'll take approx. 4 days with my 2TB drives.

Best regards,
Stefan

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: Convert RAID5 to RAID6 in a live system
  2011-03-23  9:07     ` Stefan Roese
@ 2011-03-23 11:15       ` Mikael Abrahamsson
  0 siblings, 0 replies; 5+ messages in thread
From: Mikael Abrahamsson @ 2011-03-23 11:15 UTC (permalink / raw)
  To: Stefan Roese; +Cc: Roman Mamedov, linux-raid

On Wed, 23 Mar 2011, Stefan Roese wrote:

> Thanks. I already started with this conversion, so this 
> "--layout=preserve" is not an option for me any more. But good to know 
> that this conversion should work. But its slow - it'll take approx. 4 
> days with my 2TB drives.

Also, layout=preserve I guess would make it not a proper RAID6 but a RAID5 
with a parity disk. This is not optimal long-term.

The time you mention is normal I'd say.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2011-03-23 11:15 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-03-23  7:43 Convert RAID5 to RAID6 in a live system Stefan Roese
2011-03-23  8:07 ` Mikael Abrahamsson
2011-03-23  8:14   ` Roman Mamedov
2011-03-23  9:07     ` Stefan Roese
2011-03-23 11:15       ` Mikael Abrahamsson

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