Quick and Easy ESXi Backups
First of all you need to shutdown both your desired and the VM guest Machines. You will be backing up your desired VM machine on to your VM Guest machine. The next step would be to take a snapshot of a VM. Prior to taking any new snapshot, make it sure that you have deleted any previous or undesired ones to avoid any possible inconvenience later on. This would be your starting point. Now turn on the VM guest machine to back up the disk images from your desired VM machine, so it shouldn't take a lot of time to back up ESXi.
Next up, apply the rsync to copy your VM Guest machine to the network or the attached storage (whichever applicable). If you don't have an ESXi compatible rsync you can always get one from the VMWare forums for free. Now to carry out your backup ESXI, you must now make an rsync exclude file containing these things: 000001, Snapshot and vswp. Then you will rsync the VM guest directory to the backup location off your machine. Congratulations! You have successfully completed your backup ESXi. The amount of success of your backup ESXi may vary irrespectively. One thing you should do is to have a good recovery plan in case your back up ESXi goes wrong. You will be thanking yourself in that case for doing so.
You can also backup your current EXSi configuration and restore it later on when required. To do so you would be required to use the vicfg-cfgbackup.pl command. You would also need to download either the vCLI or vCLI and launch the aforementioned command. Similarly, use the same command to restore the configuration. Often it takes a good few hours to backup ESXi machines, so in order to avoid or minimize the downtime, it is better to schedule them during night hours or when the system is not in use.