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* incremental rbd export / sparse files?
@ 2012-11-22 11:02 Stefan Priebe - Profihost AG
  2012-11-22 21:59 ` Sage Weil
  0 siblings, 1 reply; 6+ messages in thread
From: Stefan Priebe - Profihost AG @ 2012-11-22 11:02 UTC (permalink / raw)
  To: ceph-devel@vger.kernel.org

Hello list,

right now a rbd export exports exactly the size of the disk even if 
there is KNOWN free space. Is this inteded to change?

Might it be possible to export just differences between snapshots and 
merge them later?

Greets,
Stefan

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: incremental rbd export / sparse files?
  2012-11-22 11:02 incremental rbd export / sparse files? Stefan Priebe - Profihost AG
@ 2012-11-22 21:59 ` Sage Weil
  2012-11-23  6:23   ` Dietmar Maurer
  2012-11-24  0:04   ` Wido den Hollander
  0 siblings, 2 replies; 6+ messages in thread
From: Sage Weil @ 2012-11-22 21:59 UTC (permalink / raw)
  To: Stefan Priebe - Profihost AG; +Cc: ceph-devel@vger.kernel.org

On Thu, 22 Nov 2012, Stefan Priebe - Profihost AG wrote:
> Hello list,
> 
> right now a rbd export exports exactly the size of the disk even if there is
> KNOWN free space. Is this inteded to change?
> 
> Might it be possible to export just differences between snapshots and merge
> them later?

We were just talking about this the other day.

Step 1 is to create a mechanism to output a list of block ranges that 
have/have not changed between snapshots.

Step 2 is to export the incremental changes.  The hangup there is figuring 
out a generic and portable file format to represent those incremental 
changes; we'd rather not invent something ourselves that is ceph-specific.
Suggestions welcome!

sage


^ permalink raw reply	[flat|nested] 6+ messages in thread

* RE: incremental rbd export / sparse files?
  2012-11-22 21:59 ` Sage Weil
@ 2012-11-23  6:23   ` Dietmar Maurer
  2012-11-23  8:03     ` Stefan Priebe - Profihost AG
  2012-11-24  0:04   ` Wido den Hollander
  1 sibling, 1 reply; 6+ messages in thread
From: Dietmar Maurer @ 2012-11-23  6:23 UTC (permalink / raw)
  To: Sage Weil, Stefan Priebe - Profihost AG; +Cc: ceph-devel@vger.kernel.org

> Step 2 is to export the incremental changes.  The hangup there is figuring out
> a generic and portable file format to represent those incremental changes;
> we'd rather not invent something ourselves that is ceph-specific.
> Suggestions welcome!

AFAIK, both 'zfs' and 'btrfs' already have such format. 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: incremental rbd export / sparse files?
  2012-11-23  6:23   ` Dietmar Maurer
@ 2012-11-23  8:03     ` Stefan Priebe - Profihost AG
  0 siblings, 0 replies; 6+ messages in thread
From: Stefan Priebe - Profihost AG @ 2012-11-23  8:03 UTC (permalink / raw)
  To: Dietmar Maurer; +Cc: Sage Weil, ceph-devel@vger.kernel.org

Am 23.11.2012 07:23, schrieb Dietmar Maurer:
>> Step 2 is to export the incremental changes.  The hangup there is figuring out
>> a generic and portable file format to represent those incremental changes;
>> we'd rather not invent something ourselves that is ceph-specific.
>> Suggestions welcome!
>
> AFAIK, both 'zfs' and 'btrfs' already have such format.

I think zfs could be problematic again with their licenses? If not i 
would prefer that one as it is proven and stable.

Greets,
Stefan

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: incremental rbd export / sparse files?
  2012-11-22 21:59 ` Sage Weil
  2012-11-23  6:23   ` Dietmar Maurer
@ 2012-11-24  0:04   ` Wido den Hollander
  2012-11-24  6:31     ` Stefan Priebe - Profihost AG
  1 sibling, 1 reply; 6+ messages in thread
From: Wido den Hollander @ 2012-11-24  0:04 UTC (permalink / raw)
  To: Sage Weil; +Cc: Stefan Priebe - Profihost AG, ceph-devel@vger.kernel.org



On 11/23/2012 05:59 AM, Sage Weil wrote:
> On Thu, 22 Nov 2012, Stefan Priebe - Profihost AG wrote:
>> Hello list,
>>
>> right now a rbd export exports exactly the size of the disk even if there is
>> KNOWN free space. Is this inteded to change?
>>
>> Might it be possible to export just differences between snapshots and merge
>> them later?
>
> We were just talking about this the other day.
>
> Step 1 is to create a mechanism to output a list of block ranges that
> have/have not changed between snapshots.
>
> Step 2 is to export the incremental changes.  The hangup there is figuring
> out a generic and portable file format to represent those incremental
> changes; we'd rather not invent something ourselves that is ceph-specific.
> Suggestions welcome!
>

I'm not sure about the licensing and such, but doesn't VMware do 
something with their VMDK images?

There you have a base image and each snapshot is a separate file.

You have:

image.vmdk
image-delta1.vmdk
image-delta2.vmdk
..
..

You can merge all these files together again to a new image based on the 
last snapshot you feeded it.

They probably didn't use a open format to do this, but something in that 
direction is what you are looking for?

Wido

> sage
>
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: incremental rbd export / sparse files?
  2012-11-24  0:04   ` Wido den Hollander
@ 2012-11-24  6:31     ` Stefan Priebe - Profihost AG
  0 siblings, 0 replies; 6+ messages in thread
From: Stefan Priebe - Profihost AG @ 2012-11-24  6:31 UTC (permalink / raw)
  To: Wido den Hollander; +Cc: Sage Weil, ceph-devel@vger.kernel.org

Am 24.11.2012 um 01:04 schrieb Wido den Hollander <wido@widodh.nl>:

> 
> 
> On 11/23/2012 05:59 AM, Sage Weil wrote:
>> On Thu, 22 Nov 2012, Stefan Priebe - Profihost AG wrote:
>>> Hello list,
>>> 
>>> right now a rbd export exports exactly the size of the disk even if there is
>>> KNOWN free space. Is this inteded to change?
>>> 
>>> Might it be possible to export just differences between snapshots and merge
>>> them later?
>> 
>> We were just talking about this the other day.
>> 
>> Step 1 is to create a mechanism to output a list of block ranges that
>> have/have not changed between snapshots.
>> 
>> Step 2 is to export the incremental changes.  The hangup there is figuring
>> out a generic and portable file format to represent those incremental
>> changes; we'd rather not invent something ourselves that is ceph-specific.
>> Suggestions welcome!
> 
> I'm not sure about the licensing and such, but doesn't VMware do something with their VMDK images?
> 
> There you have a base image and each snapshot is a separate file.
> 
> You have:
> 
> image.vmdk
> image-delta1.vmdk
> image-delta2.vmdk
> ..
> ..
> 
> You can merge all these files together again to a new image based on the last snapshot you feeded it.
> 
> They probably didn't use a open format to do this, but something in that direction is what you are looking for?

Yes something like that would be perfect.

Stefan

> 
> Wido
> 
>> sage
>> 
>> --
>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-11-24  6:31 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-11-22 11:02 incremental rbd export / sparse files? Stefan Priebe - Profihost AG
2012-11-22 21:59 ` Sage Weil
2012-11-23  6:23   ` Dietmar Maurer
2012-11-23  8:03     ` Stefan Priebe - Profihost AG
2012-11-24  0:04   ` Wido den Hollander
2012-11-24  6:31     ` Stefan Priebe - Profihost AG

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