Thank you very much, Niall.
Cary Millsap
Method R Corporation
Author of *Optimizing Oracle Performance <http://amzn.to/OM0q75>*
and *The Method R Guide to Mastering Oracle Trace Data, 3rd edition
<https://amzn.to/2IhhCG6+-+Millsap+2019.+Mastering+Oracle+Trace+Data+3ed>*
On Thu, Feb 18, 2021 at 3:26 AM <niall.litchfield@xxxxxxxxx> wrote:
We've taken the "slot size" approach described at
https://ardentperf.com/2013/12/02/osp-2c-build-a-standard-platform-from-the-bottom-up/
and used it successfully for some years. on physical servers. We use
historic CPU usage as the key metric to determine what slot size a database
should take. Databases then get CPU_COUNT set according to the calculation.
Because a slot is a combination of CPU and memory we have found it useful
to allocate some databases additional slots that are there only to allow
historical SGA sizes to be retained. From memory, our standard is 4GB ram
per CPU, but if we find a database that historically had memory allocation
of 20GB of ram, but CPU usage was 2 CPUs then we'd allocate a standard size
of 2 slots plus another 3 slots for the memory requirement.
This works well for consolidating database on large servers on-prem
attached to a reasonably performing SAN. It's unlikely to work well for
consolidating onto a public cloud platform (I have my doubts that people
typically save money just by moving workloads there to be honest) and if
the consolidation is onto a self-hosted virtualisation platform then the
unit to allocate standard sizes to is the VM, so the database metric
gathering can still be done, but the thing that gets sized is the VM and
the database then fits within that.
On Wed, Feb 17, 2021 at 8:45 PM Cary Millsap <cary.millsap@xxxxxxxxxxxx>
wrote:
Hi everybody, from freezing cold Texas.
I have a friend who's embarking on a big project to reduce the number of
servers and licenses his company has to pay for and maintain (presumably
using VMs and PDBs and all that). Do you know of any good sources for
studying up on how to do a good job on a project like this?
Thank you,
Cary Millsap
Method R Corporation
Author of *Optimizing Oracle Performance <http://amzn.to/OM0q75>*
and *The Method R Guide to Mastering Oracle Trace Data, 3rd edition
<https://amzn.to/2IhhCG6+-+Millsap+2019.+Mastering+Oracle+Trace+Data+3ed>*
--
Niall Litchfield
Oracle DBA
http://www.orawin.info
