How To Backup ESXi Configuration

Backing up your ESXi Configuration:

 To backup your ESXi configuration you’ll be using the vicfg-cfgbackup.pl command as follows:

• Download either the vMA or vCLI
• Launch vicfg-cfgbackup.pl:
  
  C:\Program Files\VMware\VMware vSphere CLI\bin>vicfg-cfgbackup.pl --server -s name_of_the_server.bak
  
  
• Note: The backup will be stored at path:
  C:\Program Files (x86)\VMware\VMware vSphere CLI

Restoring your ESXi Configuration:

Restoring your ESXi config can be done after you have the host up and responding over the network again by using the following:

C:\Program Files\VMware\VMware vSphere CLI\bin>vicfg-cfgbackup.pl --server -l name_of_the_server.bak

Note: You will be asked to reboot the host on restore.
Backing  up multiple hosts! – There is a script to backup multiple ESXi hosts on the VMware communities site here. Also in PowerCLI here!