Performance counters are modeled using the PerfCounterInfo data object type. Each instance of a PerfCounterInfo data object contains metadata about a specific metric available from the system. The memory group (mem) of performance counters documented on this page are available from the PerformanceManager service interface. Memory Management and the VMkernelThe VMkernel maps guest physical memory to machine memory. However, because of the VMkernels unique memory-management techniques, such as ballooning, memory-sharing, swapping, and other techniques, guest physical memory-to-machine memory mapping does not have a 1:1 correspondence. Specifically, the VMkernel can:
Many of the VMkernels memory-management techniques require that VMware Tools be installed on the virtual machine. Be sure that the appropriate guest-OS-specific version of VMware Tools is installed on each virtual machine. Guest Physical Memory Compared to Machine MemoryEach counter definition in this table should be interpreted in the context of the entity to which it applies:
Memory SwappingThe VMkernel uses a "share before swap" optimization to reduce memory paging. Regardless of the page size in memory, the kernel uses a 4KB swap page size. The kernel will attempt to share 4KB pages; those pages that cannot be shared are swapped. Note: kiloBytes (KB) are more accurately called KibiBytes. For More InformationFor in-depth technical background about VMware memory management architecture, including information about ballooning, swapping, page sharing, idle memory tax, memory reclamation, touched pages, and so on, see the USENIX Association publication, Memory Resource Management in VMware ESX Server. See the Resource Management Guide for more information about configuring and managing resources, including memory. |
Counter | StatsType | Unit | Levels | Per Device Level |
RollupTypes | Labels | Entity | Instance/ Aggregate |
ESX Versions |
---|---|---|---|---|---|---|---|---|---|
active | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Active | VirtualMachine HostSystem | aggregate | |
Amount of memory that is actively used,
as estimated by VMkernel based on recently touched memory pages.
| |||||||||
activewrite | absolute | kiloBytes | 2 | 3 | average | Active write | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Estimate for the amount of memory actively being written to by the virtual machine. | |||||||||
capacity.contention | rate | percent | 4 | 4 | average | Memory Capacity Contention | ResourcePool | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Percentage of time VMs are waiting to access swapped, compressed or ballooned memory. | |||||||||
capacity.entitlement | absolute | kiloBytes | 4 | 4 | average | Memory Capacity Entitlement | ResourcePool | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Amount of host physical memory the VM is entitled to, as determined by the ESXi scheduler | |||||||||
capacity.provisioned | absolute | kiloBytes | 4 | 4 | average | Memory Capacity Provisioned | ResourcePool | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Total amount of memory available to the host. | |||||||||
capacity.usable | absolute | kiloBytes | 4 | 4 | average | Memory Capacity Usable | ResourcePool | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Amount of physical memory available for use by virtual machines on this host | |||||||||
capacity.usage | absolute | kiloBytes | 4 | 4 | average | Memory Capacity Usage | ResourcePool | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Amount of physical memory actively used | |||||||||
capacity.usage.userworld | absolute | kiloBytes | 2 | 4 | average | ||||
capacity.usage.vm | absolute | kiloBytes | 2 | 4 | average | ||||
capacity.usage.vmOvrhd | absolute | kiloBytes | 2 | 4 | average | Memory Capacity Usage by VM overhead | |||
Amount of memory used by virtual machine overhead. | |||||||||
capacity.usage.vmkOvrhd | absolute | kiloBytes | 2 | 4 | average | Memory Capacity Usage by VMkernel Overhead | |||
Amount of memory used by VMKernel overhead. | |||||||||
compressed | absolute | kiloBytes | 2 | 3 | average | Compressed | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Amount of memory reserved by userworlds. | |||||||||
compressionRate | rate | kiloBytesPerSecond | 2 | 3 | average | Compression rate | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Rate of memory compression for the virtual machine. | |||||||||
consumed | absolute | kiloBytes | 1 (4) | 4 | average (minimum) (maximum) (none) | Consumed | VirtualMachine HostSystem ResourcePool | aggregate | 5.5 6.0 6.5 6.7 |
Amount of host physical memory consumed by a virtual machine, host, or cluster.
| |||||||||
consumed.userworlds | absolute | kiloBytes | 2 | 4 | average | Memory Consumed by userworlds | |||
Amount of physical memory consumed by userworlds on this host | |||||||||
consumed.vms | absolute | kiloBytes | 2 | 4 | average | Memory Consumed by VMs | |||
Amount of physical memory consumed by VMs on this host. | |||||||||
decompressionRate | rate | kiloBytesPerSecond | 2 | 3 | average | Decompression rate | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Rate of memory decompression for the virtual machine. | |||||||||
entitlement | absolute | kiloBytes | 2 | 3 | average | Entitlement | VirtualMachine | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Amount of host physical memory the virtual machine is entitled to, as determined by the ESX scheduler. | |||||||||
granted | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Granted | VirtualMachine HostSystem | aggregate | |
Amount of host physical memory or physical memory that is mapped for a virtual machine or a host. | |||||||||
heap | absolute | kiloBytes | 4 | 4 | average (minimum) (maximum) (none) | Heap | HostSystem | aggregate | |
VMkernel virtual address space dedicated to VMkernel main heap and related data | |||||||||
heapfree | absolute | kiloBytes | 4 | 4 | average (minimum) (maximum) (none) | Heap free | HostSystem | aggregate | |
Free address space in the VMkernel main heap.Varies based on number of physical devices and configuration options. There is no direct way for the user to increase or decrease this statistic. For informational purposes only: not useful for performance monitoring. | |||||||||
latency | absolute | percent | 2 | 3 | average | Latency | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Percentage of time the virtual machine is waiting to access swapped or compressed memory | |||||||||
llSwapIn | absolute | kiloBytes | 4 | 4 | average (minimum) (maximum) (none) | Swap in from host cache | HostSystem | aggregate | |
Amount of memory swapped-in from host cache | |||||||||
llSwapInRate | rate | kiloBytesPerSecond | 2 | 3 | average | Swap in rate from host cache | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Rate at which memory is being swapped from host cache into active memory | |||||||||
llSwapOut | absolute | kiloBytes | 4 | 4 | average (minimum) (maximum) (none) | Swap out to host cache | HostSystem | aggregate | |
Amount of memory swapped-out to host cache | |||||||||
llSwapOutRate | rate | kiloBytesPerSecond | 2 | 3 | average | Swap out rate to host cache | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Rate at which memory is being swapped from active memory to host cache | |||||||||
llSwapUsed | absolute | kiloBytes | 4 | 4 | average (minimum) (maximum) (none) | Host cache used for swapping | VirtualMachine HostSystem | aggregate | |
Space used for caching swapped pages in the host cache | |||||||||
lowfreethreshold | absolute | kiloBytes | 2 | 3 | average | Low free threshold | HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Threshold of free host physical memory below which ESX/ESXi will begin reclaiming memory from virtual machines through ballooning and swapping | |||||||||
mementitlement | absolute | megaBytes | 2 | 3 | latest | Worst case allocation | |||
Memory allocation as calculated by the VMkernel scheduler based on current estimated demand and reservation, limit, and shares policies set for all virtual machines and resource pools in the host or cluster | |||||||||
overhead | absolute | kiloBytes | 1 (4) | 4 | average (minimum) (maximum) (none) | Overhead consumed | VirtualMachine HostSystem ResourcePool | aggregate | 5.5 6.0 6.5 6.7 |
Host physical memory (KB) consumed by the virtualization infrastructure for running the virtual machine.
| |||||||||
overheadMax | absolute | kiloBytes | 2 | 3 | average | Reserved overhead | VirtualMachine | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Host physical memory (KB) reserved for use as the virtualization overhead for the virtual machine | |||||||||
overheadTouched | absolute | kiloBytes | 4 | 4 | average | Overhead touched | VirtualMachine | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Actively touched overhead host physical memory (KB) reserved for use as the virtualization overhead for the virtual machine | |||||||||
reservedCapacity | absolute | megaBytes | 2 | 3 | average | Reserved capacity | HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Total amount of memory reservation used by powered-on virtual machines and vSphere services on the host. | |||||||||
reservedCapacity.userworld | absolute | kiloBytes | 2 | 4 | average | ||||
reservedCapacity.vm | absolute | kiloBytes | 2 | 4 | average | Memory Reserved capacity by VMs | |||
Amount of memory reserved by virtual machines. | |||||||||
reservedCapacity.vmOvhd | absolute | kiloBytes | 2 | 4 | average | Memory Reserved capacity by VM overhead | |||
Amount of memory reserved by virtual machine overhead. | |||||||||
reservedCapacity.vmkOvrhd | absolute | kiloBytes | 2 | 4 | average | Memory Reserved capacity by VMkernel Overhead | |||
Amount of memory reserved by VMkernel overhead. | |||||||||
reservedCapacityPct | absolute | percent | 4 | 4 | average | Memory Reserved Capacity % | |||
Percent of memory that has been reserved either through VMkernel use, by userworlds or due to virtual machine memory reservations. | |||||||||
shared | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Shared | VirtualMachine HostSystem | aggregate | |
Amount of guest physical memory that is shared with other virtual machines,
relative to a single virtual machine or to all powered-on virtual machines on a host.
| |||||||||
sharedcommon | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Shared common | HostSystem | aggregate | |
Amount of machine memory that is shared by all powered-on virtual machines and vSphere services on the host.Subtract this metric from the shared metric to gauge how much machine memory is saved due to sharing:
shared - sharedcommon = machine memory (host memory) savings (KB) | |||||||||
state | absolute | number | 2 | 3 | latest | State | HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
One of four threshold levels representing the percentage of free memory on the host.
The counter value determines swapping and ballooning behavior for memory reclamation.
2 (hard) and 3 (low): Swapping is favored over ballooning. |
|||||||||
swapin | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Swap in | VirtualMachine HostSystem | aggregate | |
Amount swapped-in to memory from disk.
|
|||||||||
swapinRate | rate | kiloBytesPerSecond | 1 | 3 | average | Swap in rate | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Rate at which memory is swapped from disk into active memory during the interval. This counter applies to virtual machines and is generally more useful than the swapin counter to determine if the virtual machine is running slow due to swapping, especially when looking at real-time statistics. | |||||||||
swapout | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Swap out | VirtualMachine HostSystem | aggregate | |
Amount of memory swapped-out to disk.
|
|||||||||
swapoutRate | rate | kiloBytesPerSecond | 1 | 3 | average | Swap out rate | VirtualMachine HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Rate at which memory is being swapped from active memory to disk during the current interval. This counter applies to virtual machines and is generally more useful than the swapout counter to determine if the virtual machine is running slow due to swapping, especially when looking at real-time statistics. | |||||||||
swapped | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Swapped | VirtualMachine | aggregate | |
Current amount of guest physical memory swapped out to the virtual machine swap file by the VMkernel.
Swapped memory stays on disk until the virtual machine needs it. This statistic refers to VMkernel
swapping and not to guest OS swapping.
swapped = swapout - swapin |
|||||||||
swaptarget | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Swap target | VirtualMachine | aggregate | |
Target size for the virtual machine swap file. The VMkernel manages swapping by comparing swaptarget against swapped. Since swapped memory stays swapped until the virtual machine accesses it, swapped memory can be greater than the memory swap target, possibly for a prolonged period of time. This simply means that the swapped memory is not currently needed by the virtual machine and is not a cause for concern. | |||||||||
swapunreserved | absolute | kiloBytes | 4 | 4 | average (minimum) (maximum) (none) | Swap unreserved | |||
Amount of memory that is unreserved by swap | |||||||||
swapused | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Swap used | HostSystem | aggregate | |
Amount of memory that is used by swap. Sum of memory swapped of all powered on VMs and vSphere services on the host. | |||||||||
sysUsage | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Used by VMkernel | HostSystem | aggregate | |
Amount of host physical memory used by VMkernel for core functionality, such as device drivers and other internal uses. Does not include memory used by virtual machines or vSphere services. | |||||||||
totalCapacity | absolute | megaBytes | 2 | 3 | average | Total capacity | HostSystem | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Total amount of memory reservation used by and available for powered-on virtual machines and vSphere services on the host | |||||||||
totalmb | absolute | megaBytes | 1 | 3 | average | Total | |||
Total amount of host physical memory of all hosts in the cluster that is
available for virtual machine memory (physical memory for use by the
guest OS) and virtual machine overhead memory.
Memory Total = Aggregate host machine memory - (VMkernel memory + Service Console memory + other service memory) | |||||||||
unreserved | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Unreserved | HostSystem | aggregate | |
Amount of memory that is unreserved. Memory reservation not used by the Service Console, VMkernel, vSphere services and other powered on VMs user-specified memory reservations and overhead memory. This statistic is no longer relevant to virtual machine admission control, as reservations are now handled through resource pools. | |||||||||
usage | absolute | percent | 1 (4) | 4 | average (minimum) (maximum) (none) | Host consumed % | VirtualMachine HostSystem | aggregate | 5.5 6.0 6.5 6.7 |
Memory usage as percent of total configured or available memory. A value between 0 and 10,000 expressed as a hundredth of a percent (1 = 0.01%). | |||||||||
vmfs.pbc.capMissRatio | absolute | percent | 4 | 4 | latest | VMFS PB Cache Capacity Miss Ratio | HostSystem | aggregate | 6.0 6.5 6.7 |
Trailing average of the ratio of capacity misses to compulsory misses for the VMFS PB Cache | |||||||||
vmfs.pbc.overhead | absolute | kiloBytes | 4 | 4 | latest | VMFS PB Cache Overhead | HostSystem | aggregate | 6.0 6.5 6.7 |
Amount of VMFS heap used by the VMFS PB Cache | |||||||||
vmfs.pbc.size | absolute | megaBytes | 4 | 4 | latest | VMFS PB Cache Size | HostSystem | aggregate | 6.0 6.5 6.7 |
Space used for holding VMFS Pointer Blocks in memory | |||||||||
vmfs.pbc.sizeMax | absolute | megaBytes | 4 | 4 | latest | Maximum VMFS PB Cache Size | HostSystem | aggregate | 6.0 6.5 6.7 |
Maximum size the VMFS Pointer Block Cache can grow to | |||||||||
vmfs.pbc.workingSet | absolute | teraBytes | 4 | 4 | latest | VMFS Working Set | HostSystem | aggregate | 6.0 6.5 6.7 |
Amount of file blocks whose addresses are cached in the VMFS PB Cache | |||||||||
vmfs.pbc.workingSetMax | absolute | teraBytes | 4 | 4 | latest | Maximum VMFS Working Set | HostSystem | aggregate | 6.0 6.5 6.7 |
Maximum amount of file blocks whose addresses are cached in the VMFS PB Cache | |||||||||
vmmemctl | absolute | kiloBytes | 1 (4) | 4 | average (minimum) (maximum) (none) | Balloon | VirtualMachine HostSystem ResourcePool | aggregate | 5.5 6.0 6.5 6.7 |
Amount of memory allocated by the virtual machine memory control driver (vmmemctl), which is installed with VMware Tools. It is a VMware exclusive memory-management driver that controls ballooning.
|
|||||||||
vmmemctltarget | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Balloon target | VirtualMachine | aggregate | |
Target value set by VMkernal for the virtual machine's memory balloon size.
In conjunction with vmmemctl metric, this metric is used by VMkernel to inflate
and deflate the balloon for a virtual machine, as follows:
| |||||||||
zero | absolute | kiloBytes | 2 (4) | 4 | average (minimum) (maximum) (none) | Zero | VirtualMachine HostSystem | aggregate | |
Memory that contains 0s only.Included in shared
amount. Through transparent page sharing, zero memory pages can be shared among virtual machines that run the same
operating system.
| |||||||||
zipSaved | absolute | kiloBytes | 2 | 3 | latest | Memory saved by zipping | VirtualMachine | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Memory (KB) saved due to memory zipping. | |||||||||
zipped | absolute | kiloBytes | 2 | 3 | latest | Zipped memory | VirtualMachine | aggregate | 5.0 5.1 5.5 6.0 6.5 6.7 |
Memory (KB) zipped. |
Back to Top of page