VMware ESXi imposes some limits on virtual machines depending on your license level and the version of ESXi you're using. This page details what the most important limits are and provides a link to VMware's PDF documentation for further details.
| Version | VCPUs / License | Memory | SCSI devices | Disk size | Release date |
|---|---|---|---|---|---|
| 4.0 | 8 / Standard | 255GB | 15 | 2TB (less 512B) | 2009-05-21 |
| 4.1 | 8 / Standard | 255GB | 15 | 2TB (less 512B) | 2010-07-13 |
| 5.0 | 32 / Enterprise | 1TB | 15 | 2TB (less 512B) | 2011-08-24 |
| 5.1 | 64 / Enterprise Plus | 1TB | 15 | 2TB (less 512B) | 2012-09-11 |
| 5.5 | 64 / Enterprise Plus | 1TB | 15 | 62TB | 2013-09-22 |
Something else to keep in mind is that prior to the 11.10.310 release all Enterprise releases were 32-bit, which supports a maximum of 8 VCPUs at the OS level. You can see the supported number of CPUs like this:
grep NR_CPUS /boot/config-`uname -r`
CONFIG_NR_CPUS=8
On our 64-bit VM, we support a maximum of 256 VCPUs at the OS level (which is far more than ESXi currently allows):
grep NR_CPUS /boot/config-`uname -r`
CONFIG_NR_CPUS=256
