[Users] Designate Master Storage Domain

[Dead Horse]

Live Migration is possible when the relevant storage server is not the one
needing to be taken offline for maintenance. Granted a proper Gluster setup
would alleviate that however when optimum performance of file backed
virtual disks is a factor Gluster is not there yet.
- DHC


On Sun, Aug 18, 2013 at 5:47 AM, Ayal Baron <abaron at redhat.com> wrote:

>
>
> ----- Original Message -----
> > Pausing the VM's can work in certain situations for simple maintenance.
> > However suppose the purpose of the storage shutdown is to move data
> around
> > for certain VM's or perhaps change that particular underlying storage
>
> Then why not live migrate the relevant disks?
>
> > filesystem or hardware. Thus some of the VM's will have to be down for
> sure
> > however pausing them all because of the aforementioned would not be an
> > option since it would take hours or days depending on the amount of data
> and
> > the degree of change.
> >
> > - DHC
> >
> >
> > On Fri, Aug 16, 2013 at 12:14 AM, Karli Sjöberg < Karli.Sjoberg at slu.se >
> > wrote:
> >
> >
> >
> > tor 2013-08-15 klockan 10:46 -0500 skrev Dead Horse:
> >
> >
> > Itamar this is true (I have noted occasional timing issues with it
> actually
> > working).
> > But what if as the administrator I have a specific storage domain in mind
> > that I would like to have become the master (in the case of more then
> two)?
> >
> >
> >
> >
> > @Karli
> >
> >
> >
> > The idea is not to not have to shut down all the VM's or the engine just
> to
> > maintenance a storage domain(s) that may happen to be on disparate
> storage
> > servers
> > .
> >
> > Yes I understood that. My suggestion was a workaround until such
> operations
> > are possible, that we use to minimize downtime as much as possible, to
> pause
> > the VM's, shut down engine, maintenance, bring engine and VM's back.
> Since
> > the VM's only was paused and engine shut down, the VM's just continue
> going
> > happily unknowing exactly from where they were, and a reboot of a storage
> > takes at most 5mins, which means 5mins total of downtime in the cloud
> > environment for that quarter, which is acceptable for just about any SLA.
> >
> > /Karli
> >
> >
> >
> >
> >
> >
> >
> > - DHC
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Aug 15, 2013 at 9:37 AM, Itamar Heim < iheim at redhat.com > wrote:
> >
> >
> >
> > On 08/15/2013 06:18 AM, Dead Horse wrote:
> >
> >
> >
> >
> >
> >
> >
> > Is there any method of designating which domain should be the master
> > storage domain or forcibly changing the role to a different storage
> domain?
> >
> > EG: Given the following example
> >
> > Storage Domain A (Master) --> NFS --> Storage Server 1
> > Storage Domain B --> NFS --> Storage Server 2
> >
> > One wants to do maintenance to Storage Server 1 but in doing so the
> > Master storage domain is hosted from Storage Server 1. Thus the net
> > result of taking down Storage Server 1 is that one must also take down
> > Storage Server 2.
> >
> > Thus we know we must shut down VM's from Storage Domain A to maintenance
> > Storage Server 1. Suppose however that VM's are running that we don't
> > want to shut down and are hosted from Storage Domain B via Storage
> Server 2.
> >
> > We would want to be able to promote Storage Domain B to Master so that
> > we can take down Storage Domain A to do maintenance to Storage Server 1.
> >
> > Once we are done with maintenance to Storage Server 1 we can bring
> > Storage Domain A back on line, re-designate it as Master if desired and
> > bring it's VM's back online.
> >
> > I know I have seen this occur automatically to a point when a Storage
> > Domain goes missing that is the Master Domain but I have not noted any
> > manual method of doing so given the above scenario.
> >
> > - DHC
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users at ovirt.org
> > http://lists.ovirt.org/ mailman/listinfo/users
> >
> >
> > my understanding is you can move the storage domain A which is master to
> > maint. engine will promote storage domain B to master and everything
> should
> > continue working as is.
> >
> >
> >
> >
> >
> >       --
> >
> > Med Vänliga Hälsningar
> >
> -------------------------------------------------------------------------------
> > Karli Sjöberg
> > Swedish University of Agricultural Sciences
> > Box 7079 (Visiting Address Kronåsvägen 8)
> > S-750 07 Uppsala, Sweden
> > Phone: +46-(0)18-67 15 66
> > karli.sjoberg at slu.se
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/users
> >
>
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