Re: Oracle 10g on Microsoft's Virtual Server

From: Glen <stromqueat_at_teldotnet.com>
Date: Tue, 19 Sep 2006 21:43:31 GMT
Message-ID: <7wZPg.19400$KA6.3999@clgrps12>

Brian Peasland wrote:

>> Why VM? Well, I think the theory is ease of disaster recovery. In
>> theory if the VHDs  (virtual hard drives) are backed up, you could just
>> dump C and D on a VM and BOOM you are up and running. I like that idea,
>> but it is all theory. Of course I am working this theory into reality.
>> I am a hardware/software guy for 11 years, but Oracle is new.

>
>
> How is this different than taking a snapshot of your server's disk
> system? Your storage vendor will be more than happy to discuss how disk
> snapshots make backups a very quick operation. Oracle 9i introduced the
> facility to halt db I/O (suspend it) while the snapshot is being taken.
>
> (snip)
>

>> In theory this would remove the lengthy restore process from tape or
>> other media. Install or flashing an IMAGE back on the server and
>> installing oracle (or even using an image with oracle on it) and then
>> importing your data would take X amount of time. This scenario takes
>> about 15 minutes. Nightly backups of the VHDs is all that is required.

>
>
> How do you handle your transactions since the last nightly backup was
> taken?
>

>> It is all still theory, but it does work with no side effects. (that we
>> have found so far)

>
>
> Lost transactions is a side effect that I can think of....
>

>> So, why go VM - everything breaks eventually (well not really :) ) so
>> they want to get back up as fast as possible with minimum loss of
>> data...... I think they are more worried of hardware failure then
>> simple problems. ---- Really unsure on this part....

>
>
> I think we're getting down to an actual requirement..."get back up as
> fast as possible with minimum loss of data". For this requirement,
> Oracle has an option called Data Guard which can be configured for zero
> data loss, or minimal data loss. The Data Guard configuration has pros
> and cons, but you do have options here.
>
> In your scenario, how do you achieve minimal data loss if you lose the
> VM and restore it from its backup? If you take the backup at midnight
> and lose the VM at 6pm, how do you get back 18 hours of transactions?
>
>
> Cheers,
> Brian
>

Could you not just restore the VM from last backup (which is very quick) , then startup mount the db, recover with backupcontrolfile and apply all the redo like you would any other database? This is assuming you have duplexed the redo to another drive or VM..

The time saving here is the time it takes to restore a VM as opposed to building a new server with OS, install and patch Oracle, then restore backed up datafiles.. Received on Tue Sep 19 2006 - 16:43:31 CDT