EVC - CPU compability for VMotion

EVC (Enhanced VMotion Compability) increases the VMotion possibilities between different processor generations. EVC is introduced from ESX v3.5 u2 and Virtual Center v2.5 u2.

Intel Nehalem processor type is supported from ESX v3.5 u4 (and VC2.5 u2 minimum, I guess)

Link to KB article

Link to Nehalem architecture on Wikipedia

Update 2011.03.18: A BL460cG6 (E5520 Nehalem 45 nm) is compatible together with a BL460cG7 (E5620 Nehalem 32 nm Westmere) in an EVC cluster with Intel Xeon Core i7 (currently second highest level for intel processors) level enabled. However, if Intel Xeon Core i7 32 nm is chosen, then only G7 blades can be used.

How to enable 64-bit in BIOS on HP server

To be able to run 64-bit VM's in VMware ESX server, then Intel-VT technology needs to be enable in BIOS. Furthermore, to enable EVC (Enhanced VMotion Compability), No-execute memory feature should be enabled, see below.

1. Go to BIOS (press F9 during boot)
2. Go to Advanced Options -> Processor Options -> Intel ® Virtualization Technology
3. Choose Enable
4. Furtermore, to enable VMware EVC, enable 'No-Execute Memory Protection' (just above Intel-VT).
5. Save and exit


NB: All hosts in your cluster should have the same BIOS settings. If not, this can result in VMotion issues.