Re: [Qemu-devel] Security for QCOW2 format

[Fam Zheng]

On Sat, 11/08 00:32, Halsey Pian wrote:
> Dear All,
> 
>  
> 
> Nice to know all of you!
> 
>  
> 
> Recently, I am reading codes of qcow2 format, in order to switch
> virtualization solution in my project from VMWare to KVM for more specific
> customization based on customer's requirements. 
> 
>  
> 
> I have one consideration related to qcow2 format in QEMU.
> 
> As you know, there is all-in-one img file for QCOW2 format even if there is
> much original data and a number of snapshots, then maybe we would get a huge
> file, and maybe we cannot use this img if it is broken due to some
> reason/exception during long term running especially for server application.
> Is there a solution for this? Or is there a strategy similar to VMWare VMDK
> format using the structure with parent pointer to manage separate sub vmdk
> files? 
> 
>  
> 
> Could you give help on it? Many thanks!

Qcow2 supports external snapshot with backing file, as alternative to internal
snapshot. It is similar to VMDK parent pointer.

There is no "sub image" in qcow2, if you mean something like two GB split
extents in VMDK.

Fam