hi,
It needs to be sized to cope with demand. So maybe look at the largest vapp that is likely to be uploaded, and the likelyhood of.serveral of these uploads happening concurrently. It will all depnend on the sive of the userbase I guess. Also if a multi-vc implementation you need to factor in capacity for deployments across vCenters
I' d say 1TB would be a safe start, thin provisioned of course ;-) You can always grow it if it's a VM
