shaunjurr ha scritto:
Just because you can run linux on VMWare doesn't mean that it is always a good idea for everything. I can't really see how one can say that it is "natural" to migrate this into a VMWare environment. Without some idea of how it is going to perform, there is no logical reason to do this at all except for not having to buy more equipment.
The age of your previous machines isn't really a factor so long as they work and their costs are not higher than new machines.
The NFS load, and the load in general, will probably increase now that you are adding a number of machines that have their OS's on the same storage in addition to cramming your mysql database over to vmware.
age of previous machine is a matter because support is getting more expensive/difficult, and they are working not as fine because of an unwise virtualization program that introduced multiple single points of failure.
All had to be redesigned, already having a vSphere infrastructure (meaning blade enclosure with good network and room for new blade servers) i guessed it was best to migrate from Xen to vSphere. We could use Xen again? No, we are too few to deal with two different technologies.
Regarding the nfs load, there are two points: first of all the disk of the VMs will be served but the FAS CPU which is currently unused. Second: the Apache VMs won't have high I/O on disk, the MySQL servers will have, but we think to use tricks to reduce it like having /tmpfs (where temp tables are created) on ram. We have got host servers with redundant ram.
Giving more details, the problem of avoiding high load on the mysql server is old one, and most of the applications have been written to use static web pages (i.e. generating static new html files when content is updated instead that retrieving the content from the db everytime a visitor requests the page). It's a news web site using 60-80Mbit/s during day hours.