Important Virtual Machines Memory metrics

Important VM Memory metrics

  1. Average memory active (highest) – the amount of memory that is estimated to be used based on memory touched.
  2. Memory granted (smallest) is a sum of all VMs running on an ESX server.
  3. Average memory Consumed (middle) – the amount of memory that the VMs actually pinned out of total configured capacity. Memory granted less memory saved by sharing.
  4. Average memory swapped in/out – virtual memory swapped to or from disk.
  5. Average memory swapped – total memory swapped out.

Memory counters to check in the VC

  • Swap used
  • Consumed
  • Active
  • Swap out
  • Usage
  • Swap in
  • Balloon – memory reclaimed.
  • Granted
  • Shared


How you know when host memory is the problem

  • Consumed memory is approaching total host memory
  • Active memory approaches total memory
  • Ballooning is occurring
  • Host swapping is occurring

Hoe you know when guest memory is the problem

  • Guest VM memory has a high % utilization in vsphere client.
  • Or View VM memory statistics inside the guest OS.

Ways to solve memory performance issues

  1. Determine where the memory utilization is coming from and find if it is valid.
  2. Reduce memory utilization if possible.
  3. Right-size VMs
  4. Reallocate resources in resource pool.
  5. Rebalance load with vmotion or DRS.
  6. Add more memory to the host or add another server to the cluster.


Interpreting esxtop Statistics

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

System Administrators Tricks