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
Change Machine SSL cert
Change the machine ssl cert to allow browsers to trust the vsphere.
Generate a CSR then for windows CA create a template to produce a certificate. Then apply the certificate and certificate chain.