Well, afaik the current workflow is like this:
I have iso domain (hosted on NFS server) a, attached to host b.
On host b I got vms c,d and e.
When I attach an ISO from a to c, the iso gets
copied from the NFS server to /var/run/vdsm/payload/{UUID}/..
When I attach the same ISO file from a to d the very same iso
file gets copied again to /var/run/vdsm/payload/{UUID_2}/ from
the NFS server.
This is unnecessary because there is already a copy of the iso in
the locale filesystem, so it would be cool if this is stored in a
way that multiple vms on the same host can utilize the same iso file
without downloading it multiple times.
I hope I described the workflow in a correct way.
If this is done already I am not aware of it, so please correct
me if I'm wrong.
An additional side effect would be that you can utilize this locally
stored iso files while the NFS server or the ISO Domain is in
maintenance mode for some reason. Or if you have a network maintenance
for the network path which leads to the ISO Domain.
Of course this just works if the host has enough ram or dedicated local
storage to store these copies.
I know that you can circumvent this, by using a locally created ISO
Domain on the host itself. But then you lose the ability of sharing
this ISO domain with different DCs, don't you?
Am 25.02.2014 14:16, schrieb Itamar Heim:
On 02/25/2014 11:55 AM, Sven Kieske wrote:
> RFE: Allow multiple local storage domains/ hosts within a cluster
> with automigration via export domains (vm has to be shut down)
> I will write a detailed BZ for this.
this can only happen after we finish the removal of storage pool aspects
(which is currently being worked on)
>
> RFE: temporary copys of iso-images on hosts which get mounted from
> iso domains into vms, this would allow to detach an iso domain while
> isos are attached and would also lower network traffic when an iso
what's the use case for detaching an iso domain making this worth while?
(it will also kill live migration, or force it to become live storage
migration for the iso)
--
Mit freundlichen Grüßen / Regards
Sven Kieske
Systemadministrator
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