From: Phil Turmel <philip@turmel.org>
To: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
Cc: Oliver Schinagl <oliver+list@schinagl.nl>, linux-raid@vger.kernel.org
Subject: Re: Expanding array with multiple devices
Date: Sat, 02 Mar 2013 12:22:43 -0500 [thread overview]
Message-ID: <51323563.4@turmel.org> (raw)
In-Reply-To: <25032068.12.1362244556592.JavaMail.root@zimbra>
On 03/02/2013 12:15 PM, Roy Sigurd Karlsbakk wrote:
>> On 03/02/2013 09:07 AM, Roy Sigurd Karlsbakk wrote:
>>>> While expanding an existing raid is as simple as mdadm --add,
>>>> followed by an mdadm --grow, How would you go about this when
>>>> expanding it with multiple devices.
>>>
>>> Given a RAID-5 on /dev/sd[bcde], I'd do
>>>
>>> # mdadm --add /dev/md0 /dev/sd[fghi]
>>> # mdadm --grow --level=6 --raid-devices=8
>>>
>>> No need to create a new RAID and then move the data.
>>
>> You missed the bit where he states he needs to use mkfs to switch
>> filesystem features.
>
> Oh, sorry. Then why not start off with an identical RAID-5, move the
> data, and then expand as above? No dangling "missing" drives, just
> plain and simple.
I agree. And the file copy to the raid5 would almost certainly run
faster than any raid6 with "missing". Then the reshape is one operation
to both expand the drive count and switch to raid6.
Phil
next prev parent reply other threads:[~2013-03-02 17:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-28 20:27 Expanding array with multiple devices Oliver Schinagl
2013-03-01 6:52 ` Mikael Abrahamsson
2013-03-02 11:52 ` Oliver Schinagl
2013-03-02 14:07 ` Roy Sigurd Karlsbakk
2013-03-02 17:11 ` Phil Turmel
2013-03-02 17:15 ` Roy Sigurd Karlsbakk
2013-03-02 17:22 ` Phil Turmel [this message]
2013-03-02 17:31 ` Mikael Abrahamsson
2013-03-02 19:14 ` Roy Sigurd Karlsbakk
2013-03-03 3:22 ` Mikael Abrahamsson
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