[Users] Storage domain weirdness (or design)

[Maor Lipchuk]

Hi Alex,
Please, see my comments inline.

Regards,
Maor


On 01/18/2013 11:34 AM, Alex Leonhardt wrote:
> Hmmm, but if I put the SPM host into Maint mode, then all the VMs would
> either be migrated or (in my case, all set to manual) not available
> during that time, correct ?
Yes, the other way that you can do to change your SPM host is to ssh
into your SPM host and restart your VDSM service (service vdsmd restart).
I would recommend you, first to check if there are no running tasks
there (vdsClient 0 getAllTasksStatuses), simply because restart of VDSM
will cancel them.
> 
> Would changing the SPM priority in the host config have the desired
> effect w/o putting the host into Maint mode ? Or can I only do that when
> the host is in Maint mode ?
You can't change your SPM host while your host is up and running.
> 
> 
> On 17 January 2013 20:42, Maor Lipchuk <mlipchuk at redhat.com
> <mailto:mlipchuk at redhat.com>> wrote:
> 
>     Hi Alex,
>     See my last respond, I add a comment inline there.
>     See my comments inline
> 
>     Regards,
>     Maor.
> 
>     On 01/17/2013 10:04 PM, Alex Leonhardt wrote:
>     > Hiya,
>     >
>     > Yes i can choose the storage domain, but I cannot force the host
>     that is
>     > to be used for creating it. Even with 1Gbit network, creating a 80GB
>     > disk / 40 GB disk is still significantly longer process than actually
>     > required when doing a "dd" of /dev/null over the network.
>     >
>     > Is it possible to manually change who is SPM master, create the
>     > disks/VMs required, and change it back ?
>     You can maintain your SPM host, and active it back again, this will
>     change the SPM to be the other host which you want.
>     > How would that change affect the running VMs / would they try to
>     migrate to the other HV ?
>     The VM migration will still be under the same cluster.
> 
>     SPM is simply used to write to the storage domains, one of the reasons
>     we use the SPM is to avoid collisions when hosts write to the same
>     storage domain.
> 
>     >
>     > Alex
>     >
>     >
>     > On 01/17/2013 07:39 PM, Maor Lipchuk wrote:
>     >> Hi Alex,
>     >> The storage domains are part of the Data Center, and should not be
>     >> related to clusters.
>     >> Clusters are used for migrating VMs, which are the qemu processes,
>     >> between hosts.
>     >> Disks are created on the storage domains regardless to clusters.
>     >>
>     >> The host which write the data in the storage domain to create the
>     disk
>     >> is the SPM.
>     >> You should have only one SPM in each Data Center (You can spot which
>     >> host is your SPM by looking at the SPM column in the hosts tab)
>     >> When you create a disk you should be able to choose the storage
>     domain
>     >> which you want the disk to be created on.
>     >>
>     >> Regards,
>     >> Maor
> 
> 
> 
> 
> 
> -- 
> 
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