Re: Oracle RAC on VM
Date: Thu, 21 Aug 2014 16:35:21 -0600
Message-ID: <53F67429.7060909_at_gmail.com>
Don't forget licensing - all CPU cores on the physical machine need to be licensed, not just those assigned to the VM. (Unless you use OracleVM).
And there is the possibility of overcommiting resources - assigning more memory, disk, CPU to all VMs on a machine than are physically available.
On the other hand, VM is not all bad - easier upgrade, migration, DR, etc.
/Hans
On 21/08/2014 4:14 PM, Kevin Lidh wrote:
>
> As a DBA, I never wanted to work on Oracle on VMware but it seems to
> be the trend. Now that I’m a manager, I’m looking to propose moving
> to RAC for HA and also back to physical machines. Since this goes
> against the strategic direction of our organization, I’m sure I’ll be
> asked why we can’t do RAC on VMs. I have my personal opinions about
> this but I was wondering what the broader audience of experts believe.
>
> Factors I’m considering are:
>
> 1)Servers closer to the storage for performance. In virtualization,
> you have an intermediary processing your requests and responses.
>
> 2)Access to all resources licensed. We keep a certain percentage of
> our hosts free to handle the load in case one in the cluster fails.
> With RAC, you have access to all the resources all the time. And
> since you have to pay for it all anyway, I see that as a good thing.
>
> 3)Performance in general. I don’t have any evidence but I can’t
> believe that another layer between my OS calls and the hardware could
> be as fast as not having that layer.
>
> Thanks in advance,
>
> Kevin
>
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Aug 22 2014 - 00:35:21 CEST