[pve-devel] KVM Live Backup performance

[Dietmar Maurer]

> I have a suggestion that would help alleviate the read and write downsides to
> this.
> 
> Create a memory buffer where the reads/writes from the VM are placed.
> When buffer is over a certain percentage, stop the backup read operations and
> flush the buffer.
> The VM can perform IO up to the limit of the memory buffer with little loss in
> performance.

That is how it works already.

Anyways, I will try to upgrade KVM to 1.7 first (many backup related changes). 
We can then test again and try to optimize further.