From: Phil Turmel <philip@turmel.org>
To: Adam Goryachev <mailinglists@websitemanagers.com.au>,
linux-raid@vger.kernel.org
Subject: Re: Converting 4 disk RAID10 to RAID5
Date: Mon, 26 Oct 2015 10:10:37 -0400 [thread overview]
Message-ID: <562E345D.5030206@turmel.org> (raw)
In-Reply-To: <562D8142.80507@websitemanagers.com.au>
Good morning Adam,
On 10/25/2015 09:26 PM, Adam Goryachev wrote:
> Hi all,
>
> I'm trying to convert a 4 disk RAID10 to a RAID5. Currently I have:
> cat /proc/mdstat
> Personalities : [raid10]
> md0 : active raid10 sdd1[2] sdc1[1] sdb1[0] sde1[3]
> 7813772288 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
> bitmap: 0/59 pages [0KB], 65536KB chunk
[trim /]
Your plan looks reasonable, if a bit long. I've done similar before.
Usually I add the new array to the LVM volume group of the original,
then pvmove the contents to the new physical volume. Let's me stay
online through the entire operation.
Anyways, it seems you are missing an opportunity to convert in place,
though. Consider setting up four small loop devices and test
conversions from r10,n2 -n4 => r0 -n3 => r4 -n4 => r5 -n4 . I suspect
you can get to your new raid5 without moving a bunch of data around.
Phil
next prev parent reply other threads:[~2015-10-26 14:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-26 1:26 Converting 4 disk RAID10 to RAID5 Adam Goryachev
2015-10-26 14:09 ` Anugraha Sinha
2015-10-26 14:10 ` Phil Turmel [this message]
2015-10-26 23:55 ` Adam Goryachev
2015-10-27 6:19 ` Anugraha Sinha
2015-10-27 6:32 ` Adam Goryachev
2015-10-27 12:13 ` Phil Turmel
2015-10-28 1:57 ` Adam Goryachev
2015-10-28 13:56 ` Phil Turmel
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