Our users reported an issue with high memory usage being reported on an lightly loaded SCB on the System monitor, and the Dashboard page of the web GUI.
Unusually high memory usage can be observed on a virtual SCB (or SSB) appliance, even when the virtual appliance is only lightly loaded, or no traffic passes through it at all.
This memory usage can't be explained with the memory usage of the applications and services on the appliance, because the sum of their memory usage is significantly lower than the usage reported by the web GUI.
In some cases the guest VM may even resort to swapping because of the low amount of free memory available.
Execute the following bash one-liner from the boot firmware to verify the issue:
mount -t debugfs nodev /sys/kernel/debug 2>/dev/null && grep -E "^(target|current):.*pages$" /sys/kernel/debug/vmmemctl ; umount /sys/kernel/debug 2>/dev/null
If the two lines returned by the command contain a non-zero number, then the ballooning driver is active.
The line beginning with "current" will give you the number of memory pages consumed by the driver. (One memory page is 4 KB in size.)
VMware's memory ballooning technology is using the unaccounted memory.
The most likely cause is that the VM-host is heavily loaded, and low on free physical memory. It uses the memory ballooning driver in the guest VMs to reclaim free memory, which can then be allocated to other running VMs.
If this situation occurs frequently, then it is a sign of the VM-host having too small amount of physical memory installed.
In order to diagnose this issue, the following steps may be taken:
In order to resolve this issue, the following steps may be taken: