[ovirt-users] Shared vs Local Storage for Datacenters

[Shani Leviim]

Hi,

I'm wondering at the moment what the actual difference is between
> Shared and Local Storage Datacenters.
>
> ​By definition, taken from here [1],
Local storage:
When you set up a host to use local storage, the host automatically gets
added to a new data center and cluster that *no other hosts* can be added
to​.
Multiple host clusters require that all hosts have access to all storage
domains, which is *not *possible with local storage.
Virtual machines created in a single host cluster cannot be migrated,
fenced or scheduled.

Shared storage:
Set up NFS shares that will serve as a data domain and an export domain.
Storage data domains can be unattached from a data center and imported to
another data center in the same environment, or in a different environment.
Virtual machines, floating virtual disk images, and templates can then be
uploaded from the imported storage domain to the attached data center.


> As far as I can see a Local DC supports NFS as well which makes it a
> more flexible DC in storage if you ask me, so why do both still exist
> ?
>
> In fact by setting a local DC, only one host can be added and there's no
high availability functionality.
According to [2], a local DC supports NFS shares for migration needs.
In case of sharing resources between more that one host, you should use a
Shared DC.


> Is it possible in a decent way to change a running Shared Storage DC
> to a Local one and Keep the NFS shares and add some local mounts for
> specific hosts ?
>
> ​Since a shared DC can support more than one host (while local DC supports
exactly one), it's not possible moving from 'Share' type to a 'Local' type.​


> I hope someone can clearify!
>
​Hope it makes more sense.​


​​
[1] https://www.ovirt.org/documentation/admin-guide/chap-Storage/
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1302185


*Regards,*
*Shani Leviim*​
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ovirt.org/pipermail/users/attachments/20171126/579b72b9/attachment.html>