From: NeilBrown <neilb@suse.de>
To: Michael Busby <michael.a.busby@gmail.com>
Cc: john.robinson@anonymous.org.uk, linux-raid@vger.kernel.org
Subject: Re: Raid5 to another raid level??
Date: Fri, 2 Sep 2011 12:19:59 +1000 [thread overview]
Message-ID: <20110902121959.173a1aa9@notabene.brown> (raw)
In-Reply-To: <CAFsPQ_97jNixHoYbMfxg9=FqXPWrsz_F1ZPSu1LTdGJA7N7Zcg@mail.gmail.com>
On Fri, 2 Sep 2011 01:54:49 +0100 Michael Busby <michael.a.busby@gmail.com>
wrote:
> As could not sleep, have just tested and works fine...here is what i have done
>
> sdd and sde are the 2 new disks
>
> mdadm -C /dev/md1 -l4 -n3 -e 1.0 /dev/sdd /dev/sde missing
>
> not sure if worth now using 1.2 as this seems the default setting if
> not specified??
>
> sdb and sdc are the old raid 5 disks
>
> echo frozen > /sys/block/md0/md/sync_action
> mdadm /dev/md0 --add /dev/sdb
> mdadm --grow --force /dev/md0 --raid-disks=4
>
> echo frozen > /sys/block/md0/md/sync_action
> mdadm /dev/md0 --add /dev/sdc
> mdadm --grow --force /dev/md0 --raid-disks=5
You can do all this in one step - 3 to 5.
> echo frozen > /sys/block/md0/md/sync_action
> mdadm /dev/md0 --add /dev/sdb
> mdadm /dev/md0 --add /dev/sdc
> mdadm --grow --force /dev/md0 --raid-disks=5
NeilBrown
>
> echo raid0 > /sys/block/md0/md/level
>
> then resize the fs...job done :)
>
>
>
> On 2 September 2011 00:50, Michael Busby <michael.a.busby@gmail.com> wrote:
> > Will test tomorrow once back in the office, hope the 4tb sync will be
> > finished by then
> >
> > I will report back my findings
> >
> >
> >
> > -- Sent from my HP TouchPadOn 1 Sep 2011 11:34 PM,
> > <john.robinson@anonymous.org.uk> wrote:
> > On 01/09/2011 22:50, Michael Busby wrote:
> >> I have found the following and see that you can convert from raid4 to
> >> raid0 fairly easy
> >>
> >>
> >> http://ubuntuforums.org/showpost.php?p=10412231&postcount=20
> >>
> >> i have a 2 disk raid5 and want to be able to convert this to raid0, i
> >> was thinking of adding a extra 2 disk and setting them up as raid0,
> >> moving the data over then adding the original raid5 disks to the raid0
> >> setup, but i see that you are unable to add disk to a raid0 setup,
> >> would it be possible to setup a raid4 with 2 disks and 1 missing, move
> >> the data from the raid5 to raid4 then add both of the original disks
> >> to the raid4 the downgrade this to raid0???
> >
> > Off the top of my head, feeling slightly sozzled (been for a few beers),
> > this might work, but as your linked post referring to a list reply from
> > Neil Brown says, you should test first. You could use some USB sticks,
> > or alternatively loopback devices are ideal for this kind of test.
> >
> > Cheers,
> >
> > John.
> >
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2011-09-02 2:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 23:50 Raid5 to another raid level?? Michael Busby
2011-09-02 0:54 ` Michael Busby
2011-09-02 2:19 ` NeilBrown [this message]
2011-09-02 9:12 ` Michael Busby
2011-09-02 10:22 ` NeilBrown
2011-09-02 10:35 ` Michael Busby
2011-09-02 12:49 ` NeilBrown
2011-09-02 13:11 ` Michael Busby
2011-09-07 1:07 ` NeilBrown
-- strict thread matches above, loose matches on Subject: below --
2011-09-07 16:26 Michael Busby
[not found] ` <CAFsPQ__YdDnJw=qgLAq10vRbNPy4B_EhkV4FU0JAfovxnw9TxQ@mail.gmail.com>
2011-10-10 21:47 ` Michael Busby
2011-10-12 4:10 ` NeilBrown
2011-10-12 9:25 ` Michael Busby
2011-10-12 10:14 ` NeilBrown
2011-10-12 16:01 ` Michael Busby
2011-09-01 21:50 Michael Busby
2011-09-01 22:34 ` John Robinson
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