I do not think that there is anything in the literature that explicity recommends or justifies this.
The main reason being that the virtual technologies have come a long way in recent years, and there used to be a limitation on how much memory could be allocated to a Virtual machine that restricted having the DB on virtual. Also, it was deemed that physical dedicated hardware would run and process faster that virtual that is shared. Again, now with the advancement of the virtual technologies that may not be the case.
There are a number of posts available around this and other discussion boards where people have Virtualised the whole environment and actually have seen an improvement (due to virtual systems only loading the device drivers required, and not all device drivers).
It depends on a number of factors for virtualisation such as how many other VM's are on the farm, allocated resources, etc. A dedicated physical has the advantage of only running that DB and not sharing resources.
An informed choice can be made when weighing up all the factors involved.
As mentioned, while it may technically work – and would be “supported”, it’s certainly not recommended to put the DB server on a virtual environment. This is because BMC Remedy products are DB intensive and any delay in processing an DB read or write will have a noticeable and potentially significant impact on overall performance.
We do have General Database Tips in the Install Guide that cover the general statement:
General database tips
To avoid a decline in the BMC Remedy AR System server performance,remember the following tips:
- Do not use a firewall between the BMC Remedy AR System server and database tiers. This can impact performance significantly.
- When possible, set up a high-speed backbone between the BMC Remedy AR System server and the database server.
- If using Ethernet, install the BMC Remedy AR System server and the database server on a separate switched network that is isolated from other network traffic.
- Avoid putting a wide-area network between the BMC Remedy AR System server and the database server.
- Make sure that each network device between the BMC Remedy AR System server and the database server is communicating at the maximum bandwidth.
While these do not call out“don’t install the database on a virtual server” explicitly, it should be an easy step in logic to see that putting any additional layer between the DB and AR System server – like a virtualization layer – may have the same negative impact.
I have heard of customers running their DB server in a virtual environment with little perceptible impact to their performance - but they had a virtual environment that met or exceeded the performance characteristics of a physical system. Plus they did extensive testing in their development environment prior to going into production to confirm that there were no unacceptable performance issues.
David J. Easter
Product Line Manager
BMC Software, Inc.