Analyzing Memory Performance with esxtop

1. Logging into vCenter and enable the ssh.
2. Log in esxi host via putty.
3. Start esxtop by typing esxtop at the command line.
4. You can view the memory performance data in esxtop by pressing ‘m’:

   

    

   The physical memory is shown by the PMEM metric.  

5. After analyzing the performance Stop the ssh 

    

   Of the metrics relating to the virtual machine worlds: 

   MEMSZ  – This is the value ,in MB, of the configured guest memory.

   GRANT – This is the amount of memory that has been granted to the world group.

   %ACTV – This is the percentage of active guest memory.

   %MCTLSZ – This is the percentage of guest memory reclaimed by the balloon driver. If this is high, it can be a sign of memory contention on the host.

   SWCUR – Current swap usage. If this is high it is a sign of memory contention on the host.

    

Metrics and Thresholds

 

Display	Metric	Threshold	Explanation
MEM	MCTLSZ	1	If larger than 0 host is forcing VMs to inflate balloon driver to reclaim memory as host is overcommitted.
MEM	SWCUR	1	If larger than 0 host has swapped memory pages in the past. Possible cause: Over commitment.
MEM	SWR/s	1	If larger than 0 host is actively reading from swap(vswp). Possible cause: Excessive memory over commitment.
MEM	SWW/s	1	If larger than 0 host is actively writing to swap(vswp). Possible cause: Excessive memory over commitment.
MEM	CACHEUSD	0	If larger than 0 host has compressed memory. Possible cause: Memory over commitment.
MEM	ZIP/s	0	If larger than 0 host is actively compressing memory. Possible cause: Memory over commitment.
MEM	UNZIP/s	0	If larger than 0 host has accessing compressed memory. Possible cause: Previously host was overcommitted on memory.
MEM	N%L	80	If less than 80 VM experiences poor NUMA locality. If a VM has a memory size greater than the amount of memory local to each processor, the ESX scheduler does not attempt to use NUMA optimizations for that VM and “remotely” uses memory via “interconnect”. Check “GST_ND(X)” to find out which NUMA nodes are used.