On Dec 10, 2004, at 8:35 AM, Doug Fairobent wrote:
I am currently trying to convince the management at my company to launch a server consolidation project using Linux on VM. All of the Intel programmers (who vastly outnumber me) are touting VMware as the server consolidation solution. Does anyone know of an analysis or study that compares the merits of VM to VMware? I hope to find some sort of ammunition I can use to promote Linux on VM. Thanks.
Well, you need to ask a bunch of questions about the application workload.
Linux on VM is wonderful for consolidating high-I/O, low-CPU tasks; print and file services are the canonical example. Linux on VM has very low overhead and you can overcommit memory quite heavily and still have a very responsive system. You also get S/390 reliability, which can be very important for some applications. And the manageability and availability of fine-grained performance tuning of VM guests is still a great deal better than VMware gives you, although VMware is making progress with that.
VMware, on the other hand, has a much higher overhead (25-30%, usually), and does not allow nearly the same level of resource overcommittal. However, if you have a lot of Intel-compiled apps that you either don't have the source for or have reason to believe that they'd be difficult to migrate to S/390 (endianness assumptions in the code, stuff like that), then this would make more sense. And if you have apps that use a lot of CPU then you're probably better off with Intel simply because CPU cycles are so much cheaper there.
If you have apps that depend on commercial products that are only available on Intel, then your choice has just been made (no, running Windows on Bochs on Linux/390 on VM is not practical, although it's pretty cool).
It really all depends on the workload, and there is unlikely to be a single "right" solution.
Feel free to contact me off-list if you want; if you have a budget for this, doing consolidation studies is something of a specialty of ours.
Adam
---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
