[pve-devel] [PATCH storage 1/1] storage/plugins: pass scfg to parse_volname

[Roland Kammerer]

On Fri, Mar 01, 2024 at 10:45:37AM +0100, Dietmar Maurer wrote:
> 
> > On 29.2.2024 16:09 CET Roland Kammerer via pve-devel <pve-devel at lists.proxmox.com> wrote:
> > All in all, yes, this is specific for our use case, otherwise
> > parse_volname would already have that additional parameter as all the
> > other plugin functions, but I don't see where this would hurt existing
> > code, and it certainly helps us to enable reassigning disks to VMs.
> > Passing in a param all other functions already get access to also does
> > not sound too terrible to me.
> > 
> > If there are further questions please feel free to ask.
> 
> Are you aware that parse_volname() is sometimes called for
> all volumes, i.e inside volume_is_base_and_used().
> 
> Would that be fast enough? IMHO its a bad idea to make a network query for each volume there...

Thanks for mentioning that, I saw that in my tests as well. We already
have infrastructure for persistent caches on the local file system in
the plugin for status(), which is also called often on all nodes and
which would otherwise hammer down the central LINSTOR controller with
too many requests.

>From what I saw the calls to parse_volname() usually happen in bursts,
my current implementation uses our existing cache infrastructure to
implement a "burst cache" valid for some seconds. I'd assume that is
then good enough, being one network request per burst.

Regards, rck