Raid10 Reshape/Grow

Raid10 Reshape/Grow

[Tim White]

I recently watched Neil's LCA2013 video, and so was wondering if RAID10 
reshape/grow is ever going to be implemented?

The way I see it, if we are adding pairs of disks to the RAID10 array 
(not necessarily the same size as current disks, but the pair being the 
same size), then we should be able to reshape to grow the RAID10.

 From what I can see, the current options are to not use RAID10 if we 
want to be able to expand later, or to use LVM over RAID1.

I'm obviously not expecting it to be in any distro's yet, but am just 
wondering what the state of these features are. I have a mdadm git 
checkout, and am willing to do testing to assist with this.

Thanks

Tim

Re: Raid10 Reshape/Grow

[keld]

I have outlined strategies to grow raid10 earlier in earlier mails on this list.
I think it is doable. Why not try to implement it like that?

Best regards
Keld

On Fri, Apr 12, 2013 at 11:55:18AM +1000, Tim White wrote:
> I recently watched Neil's LCA2013 video, and so was wondering if RAID10 
> reshape/grow is ever going to be implemented?
> 
> The way I see it, if we are adding pairs of disks to the RAID10 array 
> (not necessarily the same size as current disks, but the pair being the 
> same size), then we should be able to reshape to grow the RAID10.
> 
> From what I can see, the current options are to not use RAID10 if we 
> want to be able to expand later, or to use LVM over RAID1.
> 
> I'm obviously not expecting it to be in any distro's yet, but am just 
> wondering what the state of these features are. I have a mdadm git 
> checkout, and am willing to do testing to assist with this.
> 
> Thanks
> 
> Tim
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Raid10 Reshape/Grow

[keld]

On Fri, Apr 12, 2013 at 09:17:00AM +0200, keld@keldix.com wrote:
> I have outlined strategies to grow raid10 earlier in earlier mails on this list.
> I think it is doable. Why not try to implement it like that?

Is there a link to Neils video or some presentation notes or some such?

Best regards
keld

> 
> Best regards
> Keld
> 
> On Fri, Apr 12, 2013 at 11:55:18AM +1000, Tim White wrote:
> > I recently watched Neil's LCA2013 video, and so was wondering if RAID10 
> > reshape/grow is ever going to be implemented?
> > 
> > The way I see it, if we are adding pairs of disks to the RAID10 array 
> > (not necessarily the same size as current disks, but the pair being the 
> > same size), then we should be able to reshape to grow the RAID10.
> > 
> > From what I can see, the current options are to not use RAID10 if we 
> > want to be able to expand later, or to use LVM over RAID1.
> > 
> > I'm obviously not expecting it to be in any distro's yet, but am just 
> > wondering what the state of these features are. I have a mdadm git 
> > checkout, and am willing to do testing to assist with this.
> > 
> > Thanks
> > 
> > Tim
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Raid10 Reshape/Grow

[NeilBrown]

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On Fri, 12 Apr 2013 10:42:57 +0200 keld@keldix.com wrote:

> On Fri, Apr 12, 2013 at 09:17:00AM +0200, keld@keldix.com wrote:
> > I have outlined strategies to grow raid10 earlier in earlier mails on this list.
> > I think it is doable. Why not try to implement it like that?
> 
> Is there a link to Neils video or some presentation notes or some such?

both are linked here:

http://blog.neil.brown.name/2013/02/lca-raid/

NeilBrown

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