On Fri, 2023-12-22 at 14:05 -0300, Jorge Visentini wrote:
> The link you provided helps me a lot.
>
> Thank you very much for the prompt response!
repsonces inline
>
> Em sex., 22 de dez. de 2023 às 14:04, Jorge Visentini <
> jorgevisentini@gmail.com> escreveu:
>
> > I meant by HA, it's HA of instances... if a host goes down, it will
> > automatically rise to another host.
> >
> > Sorry my english kkkkk
> >
> > Em sex., 22 de dez. de 2023 às 13:42, Rajat Dhasmana <rdhasman@redhat.com>
> > escreveu:
> >
> > > Hi Jorge,
> > >
> > > With the LVM driver:
> > > 1. Live migration should be supported although nova team can confirm
yes it is we lvm it in our default live migration job
> > > 2. I don't know what you mean by HA instances (maybe it's a nova specific
> > > thing which again they can confirm)
no this is an ovirt or enterprise virt feature which tripleo also supprot that was reject by the nova project.

instance ha uses pacemeaker similar external monitoring solution to automaticaly evacuate or migrate instnace
when the hyperisior hosting the vm has a detectable issue like a failure of a disk in a raid array ro power supply.

with the discontinuation of tripleo using a service masakari https://docs.openstack.org/masakari/latest/
is generally what i recommend for people not using redhat openstack.(redhat openstack does not productise masakari)
if you are using upstream openstack or a distobution where its aviabel however it is worth evaulating for
this usecase.

> > > 3. Volume Snapshot is supported with the LVM driver (and it is one of the
> > > core features required for a driver to be included in the cinder codebase)
> > > 4. For a list of driver specific features, you can refer to the Cinder
> > > support matrix[1].
> > >
> > > Hope that helps.
> > >
> > > [1]
> > > https://docs.openstack.org/cinder/latest/reference/support-matrix.html
> > >
> > > Thanks
> > > Rajat Dhasmana
> > >
> > > On Fri, Dec 22, 2023 at 8:19 PM Jorge Visentini <jorgevisentini@gmail.com>
> > > wrote:
> > >
> > > > Hi all!
> > > >
> > > >
> > > > My scenario:
> > > >
> > > > We currently use oVirt and are studying the possibility of migrating to
> > > > OpenStack in the future.
> > > > Today we use Storages Enterprise 3PAR and Dell PowerVault. I've even
> > > > tried to integrate 3PAR, but it's too complex for me for now...
> > > >
> > > > Stupid question... If I work directly with LVM, that is, deliver a LUN
> > > > to all my hosts, create an LVM and deliver it to Cinter, will I have the
> > > > Live Migration, HA instances, snapshot and other features ?
if i understand correctly what you are descibign is host mounting a san lun on each
of your sotrage nodes and then using the LVM driver to partion that lun and rexport
it form the cidner volume storage nodes?

that could work but i suspect the performance would suffer unless you have the a very
high bandwith connetion to the san or lun.

one option to consider is isntead of using cinder volumes with lvm driver is to just confiugre
nova to use local stoarge and mount the nova state dir on a lun form the san

i.e. on all host map /mnt/remote_stroage to the same lun. then configure nova state dir to
/mnt/remote_storage/$hostname/nova instead of /var/lib/nova

that will mean that the local storage is treated as shared storage 
(you can do the same thing with an nfs share instead of a lun)
so nova will know it does not need to copy the vm data when live migarting or cold migrating
it also means on an evacuate the vm data will not be lost.

normally if you use local stoarge with nova and you evecaute the root disk is recreatred form the
glance image on the new host.

if you have dell powervalut or 3par you woudl likely be best configuring cinder to use there dedicated drivers
instead of using lvm as the lvm driver does not currently supprot managing volumes in a ha manner.
i.e. if the cinder volume process that managed the lvm volume is offlien its not possibel to deploy a second
instnace in an acitve/passive ro active active manner to

in yoru config as the storage would be form a san it would be possibel to have active/passive or active acitve lvm but
that would requrie code development in the lvm driver that is not currently planned.
basicaly usign somethign like tooz to implement a distibuted lock managere/leader election.

if you use the vendor specific storage driver hwoever they should already allow active/active or active passive
toplogies wehre you can have multiple isntance of cinder volume managing the same storage array.

> > > >
> > > > Cheers!
> > > > --
> > > > Att,
> > > > Jorge Visentini
> > > > +55 55 98432-9868
> > > >
> > >
> >
> > --
> > Att,
> > Jorge Visentini
> > +55 55 98432-9868
> >
>
>