From: NeilBrown <neilb@suse.de>
To: Michael Muratet <muratetm@gmail.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: Add disks and convert level 0 to level 5
Date: Thu, 11 Sep 2014 10:27:19 +1000 [thread overview]
Message-ID: <20140911102719.053a5d5c@notabene.brown> (raw)
In-Reply-To: <8CF94689-0AD6-4B87-BC0C-815F794549E7@gmail.com>
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On Wed, 10 Sep 2014 11:15:24 -0500 Michael Muratet <muratetm@gmail.com> wrote:
> I have a two-disk RAID0 system that is working splendidly, thanks to the list for the help.
>
> I managed to get my hands on more identical disks and since I have the disks and because I'm adding precious data, I'd like to add two more disks and grow to RAID5.
>
> I have partitioned the two new drives to type 'fd', /dev/sde and /dev/sdf
>
> I believe the command to accomplish the change is this:
>
> mdadm /dev/md0 --grow --level=5 --add /dev/sde /dev/sdf
>
> Following the old adage "measure twice, cut once", is this syntax correct? Is there any danger of data loss in such a conversion?
I recommend creating a few loop-back devices and experimenting.
i.e.:
create some 100M files.
use "losetup" to turn them into block devices.
create an 2-device raid0
try converting it as you suggest.
You find it doesn't do quite what you expected, but should be easy to fix.
Providing your new devices are reliable (as least read/write the entire drive
once if you feel at all cautious) there is no particular danger of data loss.
NeilBrown
>
> Thanks
>
> Mike--
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next prev parent reply other threads:[~2014-09-11 0:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-31 12:43 Converting RAID5 to RAID0 Mike Muratet
2014-08-31 17:13 ` Robin Hill
2014-08-31 22:31 ` NeilBrown
2014-09-10 16:15 ` Add disks and convert level 0 to level 5 Michael Muratet
2014-09-11 0:27 ` NeilBrown [this message]
2014-09-17 14:59 ` Michael Muratet
2014-09-17 15:15 ` Robin Hill
2014-09-11 7:27 ` Robin Hill
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