[libvirt-users] Create qcow2 v3 volumes via libvirt

[Gionatan Danti]

Il 01-05-2018 10:56 Daniel P. Berrangé ha scritto:
> qcow2 is widely used in production at large scale in general. Just not
> with internal snapshots - almost everything uses external snapshots,
> aka backing file chains.
> 
> The QEMU community still tends to discourage use of internal snapshots.
> There are not even any QMP monitor commands to use them - you are 
> forced
> to use the legacy HMP interface to QEMU for mgmt. All of the workaround
> providing interesting block storage mgmt is focused on external 
> snapshots
> (aka the backing_file option). There are some technical downsides to
> internal snapshots IIUC, such as inability to free the space used by 
> the
> internal snapshot when it is deleted, loading/saving snapshots blocks
> execution of the guest OS, and probably more I've forgotten about.
> 
> The only nice thing about internal snapshots is simplicity of mgmt, and
> that is a very nice thing indeed, which is why virt-manager has code
> to support that - it was much easier to add that code for external
> snapshots. Just a shame about all the downsides :-(

So internal snapshots remain something very useful for lab/tests, but 
are not recommended for regular use in production environment, right?

Thanks.

-- 
Danti Gionatan
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