On Sun, Jun 10, 2018 at 5:15 PM, Nir Soffer <nsoffer@redhat.com> wrote:

On Sat, Jun 9, 2018 at 4:25 PM Vinícius Ferrão <ferrao@if.ufrj.br> wrote:
Hello,

I’m planning to install Oracle 11g on a VM inside oVirt. I already knew about the licensing hell of running Oracle 11g on a virtualized environment.

The question is about snapshotting Oracle 11gb when the VM is running. Is this supported?

Supported by ovirt, not sure that by Oracle :-)

For example, on VMware and XenServer there’s the quiesce option to make the filesystem, with a little help from the guest agent, to be in an a good state for snapshots. But in oVirt, how this is handled? If supported, which operating systems are compatible with the feature?

In ovirt we use libvirt's virDomainFSFreeze[1] and virDomainFSThaw[2]
to freeze guest file systems during a snapshot.

On the guest side this uses qemu guest agent (which you must install),
to run application specific scripts when freezing or thawing the file
systems[3].

I guess oracle or someone an provide scripts to hook to qemu-guest-agent,
or you can write them yourself base on oracle documentation.

[1] https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainFSFreeze
[2] https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainFSThaw
[3] https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/virtualization_deployment_and_administration_guide/sect-using_the_qemu_guest_virtual_machine_agent_protocol_cli-libvirt_commands

Nir

See this thread opened by me in March regarding freeze-hook script and its freeze/thaw options:

https://lists.ovirt.org/archives/list/users@ovirt.org/thread/J65N7E2PY3KWUCZE2OGFVCKKWXKFDSRI/

Basically you could run the old-style statement of "alter database begin backup" in your freeze section and "alter database end backup" in your thaw section.

This way the contents of your snapshot will be consistent from an Oracle RDBMS point of view.

This is true of course only if you run your RDBMS in archive log mode.

In case of noarchive mode, you should shutdown your RDBMS in your freeze phase and start it again in your thaw phase.

Please note also that on Linux Oracle RDBMS tipically uses direct and asynchronous I/O, and so bypasses the caching at OS level.

Freeze of the filesystem storing the datafiles doesn't give you safety for Oracle RDBMS.

I have used with success this begin backup / end backup strategy both in oVirt with its snapshot functionality and using storage based snapshots, both on AIX and on Linux (with Netapp and IBM storage arrays).

With success meaning that the restore also works ;-) Make your restore tests when using in oVirt.

HIH,

Gianluca

BTW: it seems I didn't receive the OP first e-mail to the list (or I did delete it for error, without noticing... ;-)