Re: Oracle RAC vs VM WARE

On May 11, 11:11 pm, EscVector <J..._at_webthere.com> wrote:
> On May 11, 11:47 am, Valentin Minzatu <valentinminz..._at_yahoo.com>
> wrote:
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> > On May 11, 11:42 am, "fitzjarr..._at_cox.net" <fitzjarr..._at_cox.net>
> > wrote:
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> > > On May 11, 10:24 am, sybrandb <sybra..._at_gmail.com> wrote:
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> > > > On May 11, 5:17 pm, "ame..._at_iwc.net" <ame..._at_iwc.net> wrote:
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> > > > > Hi All,
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> > > > > I'm not real familiar with either of the two technologies I am posting
> > > > > about, but, we are setting up 2 new servers to run 5 database
> > > > > instances.
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> > > > > Currently we have 5 older machines, and they are about to go. We are
> > > > > trying to decide if it would be better to run VM WARE and have 5
> > > > > virtual machines between the 2 new machines, with the databases
> > > > > replicating themselves on the other for failover.
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> > > > > OR
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> > > > > Run Oracle RAC.
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> > > > > >From what I understand, RAC will make better use of resources should
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> > > > > one instance need it. But I think we're talking about multiple Oracle
> > > > > Homes on the same box right?
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> > > > > Can anyone offer some feedback maybe on some of their experiences??
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> > > > > Thanks!
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> > > > For once, please do some homework prior to posting
> > > > For instancehttp://www.orafaq.com/faq/rac
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> > > > Other than that vmware is to RAC as is apples to pears.
> > > > They are two completely different concepts.
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> > > > --
> > > > Sybrand Bakker
> > > > Senior Oracle DBA- Hide quoted text -
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> > > > - Show quoted text -
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> > > I was thinking more like bagels and lox; they aren't the same but they
> > > can go together.
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> > > David Fitzjarrell- Hide quoted text -
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> > > - Show quoted text -
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> > Only by running 2/3 instances on a single box you pay a substantial
> > penalty in terms of CPU, memory and I/O bandwith. Adding a vritual
> > machine to the mix will only make the whole thing slower. Can you not
> > consolidate the 5 into 1 and then either replicate to the other
> > machine or rac them together?
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> I have no problems running multiple instances or vm on the same
> machines. In fact, some vm images run faster than native. It all
> depends on how you set it up.
>
> If you have to ask, then stay away from RAC.- Hide quoted text -
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> - Show quoted text -

EscVector, I am arguing on the fact that VMs can be tuned to run faster than the native O/S although I would have to see it (not intention to flame anybody here).

I doubt though that 3 VMs, each with an Oracle instance running inside, will perform better than single Oracle instance on the same hardware.

On the other hand, RAC may or may not be the right choice depending on the business requirements: RAC gives some flexibility in terms of HA, but not at the same level with replication (two distinct sites/ databases). Each of the two has pros and cons and making a call one versus the other without knowing the exact business case is a bit of a stretch.

Valentin
Valentin Received on Sun May 13 2007 - 16:14:24 CDT