Vsphere

Reset vSphere Appliance Root Password

To reset the root password when you don't know it you have to reset it at the command line before boot.

Press "e" while booting to boot into the GRUB edit menu

Add the following to the end of the config line beginning with "linux"

rw init=/bin/bash

Press F10 to reboot which will then boot into a bash shell as the root user. Change the root password with:

passwd

Then reboot:

reboot -f

Sizing VMs

When choosing number of cpus per socket of VMs you want to pay attention to the processors of the host the vms are running on. You want to maximize the number of vNUMA nodes that are available to the VM. This is based on the architecture of the processors in the host.

By using the least cores per socket you will usually get the best performance.

Be careful as some applications can only use one socket, SQL servers can cause a problem here where you want more cores in the socket.

See here for detailed information https://blogs.vmware.com/vsphere/2013/10/does-corespersocket-affect-performance.html

Performance Monitoring

Monitor the vCenter appliance resources - you can use the VAMI or ssh into the vCenter appliance and use "vimtop"

Poor performance on vSphere Client or other services

poor performance can be caused by lack of memory. Check memory used by services with the following command:

cloudvm-ram-size -J <service name>

cloudvm-ram-size -J vsphere-ui

Change the heap size for a specific service:

cloudvm-ram-size -C <ram in MB> <service name>

cloudvm-ram-size -C 700 vsphere-ui