The last section is Resource Settings, I guess most are obvious (like Reservation, Limit, Configured, Shares) but the two that might not be are: (Did you notice it changed from 61MB to 102MB.) Active is the amount of memory actively used, again it is an estimate done by statistical sampling. The documentation describes it as “the amount of memory that has never been referenced by the guest”. There’s one which I couldn’t really explain which is Unaccessed. Swapped the amount of memory reclaimed by VMkernel swapping, Compressed is the amount of memory stored in the VMs compression cache and Ballooned is the amount of memory reclaimed by the Balloon Driver. Swapped, Compressed and Ballooned speak for itself in my opinion but lets be absolutely clear here. Shared is the total amount of memory shared by TPS. In other words 1.32GB is physically stored. Private is the amount of memory that is physically backed by the Host. This is the part where it gets slightly more complicated. I guess you could do the math easily:Ĭonsumed = Private + Overhead Consumption The Overhead Consumption is the amount of memory being consumed for the virtualization overhead, as you can see it is less than what the VMkernel expected to use as mentioned in the first screenshot. In other words, out of the 2GB provisioned currently 1.36GB is being consumed by that VM. The Memory section contains three sub-sections and I have carved them up as such:Īgain, Consumed is the amount of machine memory currently allocated to the VM. Looking at the tab I guess it is obvious that this one contains more details and is more complex than the summary tab: The second tab that contains details around memory is “Resource Allocation”. Now it should be pointed out here that this is an estimate calculated by a form of statistical sampling. To make it a bit more complex it should be noted that in the “Performance Tab” the “Consumed” Counter doesn’t actually include Memory Overhead!Īctive Memory more or less already explains it, it is what the VMkernel believes is currently being actively used by the VM. This also includes things like memory overhead, that also means that Consumed can be larger than what has been provisioned. Consumed Host Memory is the amount of physical memory that has been allocated to the virtual machine. This section shows again two fields related to memory:Ĭonsumed and Active is where it becomes a bit less obvious but again it isn’t rocket science. That brings us to the Resources sections: This typicall would include things like page tables, frame buffers etc. Memory Overhead is the amount of memory the VMkernel thinks it will need to run the virtualized workload, in this case 110.63MB. This is the amount of memory you provisioned your VM with, in this case 2048MB. In the screenshot above you can see 2 fields related to memory: It appears that there is a lot of confusion around this topic and that probably comes from the fact that some of the Performance Metrics are named similarly but don’t always refer to the same. The first tab that we will discuss is the Summary tab. There are a couple of places where memory details are shown on a “VM level” within the vCenter client. I received a question last week from a former colleague around vCenter Memory Metrics.