Advice for Large datastore for D2D backup?

[vmthunder]

Would you guys mind sharing your thoughts on my options (or your recommendations) for doing D2D backups of my workstations - which will start our around 2TB of data but will ultimately end up in the 4-5 TB range? I was hoping to install ESXi 4.0 on a DL365 G5 to run the Linux VM's (and a few others). For the backend I will have a SATA NAS with eight 1TB drives in a RAID 6 that supports NFS or iSCSI. Would I have to go with RDM? I can't seem to settle on a good strategy!

[DSTAVERT]

Why would you need to store backups inside a VMDK? You can use NFS or iSCSI directly attached or accessed by the guest.

[vmthunder]

Good point. So I would use the iSCSI initiator either from the host or the guest OS. Makes sense. Preferrably from the host - right?

Along those lines, I'll have a 6 TB array but is there a LUN size limit? If so, once my data size gets close to that, what are my options? Would thin provsioning be an option? (I'm probably mixing technology facts - forgive me). Thank you.