LVM snapshot option

[Halgeir]

Can someone explain to me what happens "technically" when Proxmox takes snapshot backup of a running virtual KVM machine on a LVM storage?

The reason why I ask is that I always use the "backup stop option" on windows servers to keep a consitance backup image.
Can you be sure that images of servers with running databases a keep in a consitance state when "backup snapshot option" is used.

)-|algeir

 

[Halgeir]

It's seems like no one knows this? Well. Then I have to test it myself. :|

 

[udo]

It's seems like no one knows this? Well. Then I have to test it myself. :|

Hi,
no - the knowledge is public - look at wikipedia

pve create an snapshot and for all writes the original content was copied to the snapshot - so the snapshot don't change the content while the lvm can be used like before.
But the snapshot don't see changes, which are not written to the disk (caches) in the time which the snapshot will created

After backup the snapshot can be deleted...

Udo

 

[escoreal]

Is there some misunderstanding?

There aren't used any "LVM" snapshots for backup in Proxmox VE since 2.3

I think that this is the technical discussion for the implementation:
http://pve.proxmox.com/pipermail/pve-devel/2012-November/thread.html#4625

And it looks like that that at the moment the same discussion from this thread is repeated (write perfomance with slow backup storage..)

esco

 

[udo]

Is there some misunderstanding?

There aren't used any "LVM" snapshots for backup in Proxmox VE since 2.3

I think that this is the technical discussion for the implementation:
http://pve.proxmox.com/pipermail/pve-devel/2012-November/thread.html#4625

And it looks like that that at the moment the same discussion from this thread is repeated (write perfomance with slow backup storage..)

esco

Ooops,
sorry - in this case I wasn't up to date.

Udo

 

[Halgeir]

Thank you!