I was asked for a clear definition of Consumed, Active and Granted memory statistics for VMs in a vCenter performance charts, I was a bit lost for words so research ensued.
Active is the memory recently accessed by the guest OS in the VM.
Granted – is the amount of RAM that the VMkernel has given to the VM based on the demand by it.
Consumed is the Granted memory less Shared, Shared being the memory from that VM that is being shared with other VMs by the Transparent Memory Page Sharing mechanism.
If you fancy reading more then here is a document from USENIX .
Some other stats;
-
Memory Overhead is the virtual hardware, the bigger the VM in terms of RAM, CPU and PCI devices the bigger the overhead.
Memory Swapped is the amount of the VMs memory that has been swapped out to its VMkernel swap file (.vswp).
Memory Usage is the percentage of the VMs Configured memory that is active.
Thanks to Ranjith, Sarah and H.
