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From Ahmad Emneina <aemne...@gmail.com>
Subject Re: Slow snapshots with KVM
Date Wed, 30 Jan 2013 21:14:49 GMT
KVM does a snapshot of the whole disk, as opposed to delta's like
xenserver. Which is why your kvm snapshots take ages to copy to secondary
storage.


On Wed, Jan 30, 2013 at 12:59 PM, Paul Angus <paul.angus@shapeblue.com>wrote:

> Hi Andrei,
>
> CloudStack snapshots are currently best thought off as back-ups rather
> than snapshots.
>
> Although CloudStack leverages the hypervisor's native snapshot technology,
> it then copies/movies the hypervisor level snapshot to secondary storage.
>  CloudStack doesn't declare the snapshot task finished until the snapshot
> has finished copying to secondary storage which can take a long time
> especially if you've got 100GB+ images.
>
> Given that you can't simply 'roll-back' a VM to its snapshot state, as I
> say, it's best to think of them as backups rather than snapshots.
>
>
> Regards,
>
> Paul Angus
> S: +44 20 3603 0540 | M: +447711418784
> paul.angus@shapeblue.com
>
> -----Original Message-----
> From: Andrei Mikhailovsky [mailto:andrei@arhont.com]
> Sent: 30 January 2013 17:25
> To: cloudstack-users@incubator.apache.org
> Subject: Slow snapshots with KVM
>
> Hello guys,
>
> I was wondering if there is a way to speed up the creation of snapshots in
> CS + KVM? It seems that every time the snapshot is created an entire vm
> disk image is copied over from primary to secondary storage which could
> take ages if your images are 100GB+. I remember that taking images in
> vmware / xenserver takes minutes if not seconds. Does the problem relate to
> KVM or is it a CloudStack design issue of separating primary and secondary
> storage?
>
> Many thanks
>
> Andrei
> ShapeBlue provides a range of strategic and technical consulting and
> implementation services to help IT Service Providers and Enterprises to
> build a true IaaS compute cloud. ShapeBlue’s expertise, combined with
> CloudStack technology, allows IT Service Providers and Enterprises to
> deliver true, utility based, IaaS to the customer or end-user.
>
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