We have now reached the capacity for rack space, UPS and Airco and are investigating virtualisation of as many systems as we can. We have taken advice and the consultant has been running monitoring on all servers. The results of this suggests that it is not a good idea to virtualise our SQL cluster. We do also run Sharepoint MOSS2007 databases on this cluster along with SIMS and a number other management and MIS databases. So, we will be building a new physical SQL 2008 Cluster to host these.
SIMS:
However, I am very interested in the comments about SIMS on Hyper-V posted here. With the high level of maintenance it requires, the fact that it has to have part of its application tier on the SQL box itself, and its requirements for file locations (more in a bit). I am looking at moving this to its own virtual server.
I have found that SIMS is not particularly happy living on a cluster (not cluster aware). When upgrading I have to do registry updates to the second cluster node. I have never known failover to just work for SIMS without some intervention. My other databases failover fine. In an ideal world it is good to separate logs from datafiles. Not in SIMS. Their DBAttach utility and System Manager application (more application installations on my database server) seem to require that the log files are in the same location as the data files.
So, now we move SIMS to Hyper-V. Not such a simple process as SIMS is our main MIS system and feeds data into nearly all of the others (Sharepoint, finance, transport and more) as well as into AD. Digging this lot out and re-establishing all the connection strings etc it going to be fun.
SHAREPOINT
It may be of interest to those using MOSS2007 that the results of our monitoring suggest that we should virtualise the two Front-end Web servers, but not the index server as disk IO is high.
OTHER ROLES
Out of 46 physical servers we reckon that virtualisation will have no negative (and possibly positive)
impact on performance for 20 of these. NB these are not 20 server roles as we have a fair bit of clustering.
Adrian
"One hundred idiots make idiotic plans and carry them out. All but one justly fail. The hundredth idiot, whose plan succeeded through pure luck, is immediately convinced he's a genius." Iain M Banks