Hi,
we currently have a 100% virtualized environment for SAP applications. Adding to that we have a Distributed environment where the Central Services are installed on a WFC setup, the application servers and central instance on a VM host. All on windows 2008 R2.
in my experience with WFC on VMware, it is highly complex and many areas which need to be carefully considered and configured. This needs a Support team with good skills and any incidents are difficult to troubleshoot due to the many moving parts. Due to this I have seen more failures on a WFC setup than I would have seen on a standalone Central Services/Gateway installation.
I am looking to see if a single host setup with VMware FT(fault Tolerance) will be a better setup I have read all papers and recommendations from VMware and SAP where they say why a WFC is a better solution but I am looking for a more practical solution. So far I only see the following downsides with a VMware FT based setup.
- 1 CPU limitation, yes that is a big one but if we install only the Central Services on the system, it should be fine. I have seen our WFC systems which has 2 CPU but I don't see a utilization of 10-15% ever.
- Rolling patching for OS patches - This is a big one, I am not sure how patching will work in a FT scenario, will I have to reboot the box which means downtime on the SAP Services, We usually use a simple failover for this and patch/reboot the systems one node at a time with limiting the downtime on the SAP application to the time it takes to failover the services to the other node. I have asked the question to VMware on how FT can be manipulated here but I think in the long run I can convince my business for a slightly more outage if it means a more stable SAP environment.
Looking for more practical suggestions and pre-cons to this approach.
regards
Yogesh