For a standalone ESXi setup with around 20 VMs, I recommend considering Veeam Backup Essentials. We have utilized this edition in similar small customer ...
Simply add your VMware® and Hyper-V to Hyper Data Protector's Inventory, then follow the Backup Job Wizard to create your backup tasks. You can back up all the ...
I use xsibackup to do it. Each host mounts the same NFS share as a native datastore. It's as simple as telling xsibackup the NFS datastore is it's backup ...