On Mon, May 06, 2024 at 10:03:23 +0300, Marius Vollmer wrote:
Peter Krempa <pkrempa(a)redhat.com> writes:
> On Thu, May 02, 2024 at 14:14:25 +0300, Marius Vollmer wrote:
>
>> We have been asked to prefer the "external" over the
"internal"
>> snapshot format, at least on RHEL. I haven't yet figured out why, and
>> consequently I am struggling with deciding how hard the Cockpit UI
>> should push people towards external snapshots.
>
> This is because development preferentially went into external
> snapshots. This unfortunately also meant that internal snapshots were
> neglected.
I see, thanks! So, would it be fair to say that internal snapshots are
deprecated by upstream libvirt itself (since 0.10), not just in RHEL?
No that is not fair to say from upstream point of view. We do not plan
to remove the functionality and will accept any form of improvements.
Same applies for qemu.
>> [...] That sort of thing would help me a lot to figure out
what
>> Cockpit should be doing on platforms other than RHEL.
>
> I don't think having different behaviour is a good idea.
Yes, it's also less work. :)
>> And how well (or how soon) can external snapshots be expected to work?
>
> Very technically libvirt already expects external snapshots to work.
> Said that it's a relatively recent implementation so there may be bugs.
> [...]
> Please do report them including steps how you managed to break stuff.
Will do! To be fair, most of my troubles were probably caused by using
external snapshots wrong (such as using --diskspec sda,source=blah
without knowing what I was doing and creating broken snapshots that
way), and Cockpit will of course prevent people from making those
mistakes.
Libvirt shouldn't allow creating overtly broken snapshots either.
That said there are multiple ways that users can shoot themselves into
the foot, which can't be validated/refused as those make sense in
certain scenarios.
Either way make sure to report anything broken, we can at the very
least improve documetation, if there's nothing we can fix code-wise.