Greetings to all.
I'm currently running ESXi 3.5u3 on several boxes and I've noticed some strange behavior with the memory overhead relating to a few Linux based VM's when VMI Paravirtualization is enabled.
These VM's are vastly the same and are all based off a single core image (so the underlying OS is identical).
They are running Gentoo Linux (x86), with a 2.6.x kernel, VMI support enabled in the kernel config and under the Virtual Machine configuration (Paravirtualization). The guest OS is set to "Other Linux (32-bit)". Open-vm-tools has been installed in the VM's, ESXi reports the VMware Tools as OK, along with the hostname and guest OS IP's. Guest shutdown/restart works just fine.
Each VM is running with one vCPU and 128MB of RAM.
After 24 hours of operation (and these VM's idle 99% of the time), the Memory Overhead for each VM was anywhere from 650-800MB (!!!) and slowly expanding with no signs of stopping. On a VM with 128MB of RAM, this is ridiculous. "Guest Memory Usage" is around ~10-37MB per VM, and "Host Memory Usage" is anywhere from 256MB to 560MB.
If I reboot these VM's, all the values reset to what I'd consider normal. Memory Overhead drops to around 75MB (but starts to increase), Guest & Host Memory Usage are both sub-100MB. This begins to increase slowly- by about 0.20MB every few minutes, and doesn't stop.
Disabling VMI Paravirtualization seems to have fixed the problem (I think? I just rebooted the VM's with VMI disabled).
Is this a known issue or is there some sort of memory leak associated with VMI paravirt?
-SC