Thank you for the answer, Richardson.
We did purchase the vSphere Essentials Kit and the vCenter 5 Essentials. I altered The Plan a little. I wanted to backup before updating to ESXi 5.5 so I installed the Essentials licence key. Then downloaded Veeam Free B&R. I tried some backups to tape which worked quite well. I tried Veeam to zip on the smaller VMs (~100GB) and that was also successful. I then tried Veeam to zip on the large VM (1.6TB) and after 12 hours and at 33% that VM slowed drastically until I stopped the backup and killed the processes. The drive I was backing up to has space, but I don't think there is room on the datastore for the snapshot.
I am unable to install the vCenter Server; I didn't want to put it on one of the VMs, and the only other available machine is an old Dell Poweredge. vCenter Server won't install on its processor type (P III Xeon).
Thanks again,
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David Chapman