To start, I've never used Data Domain before. We just implemented Veeam backing up to a Dell Server + DAS as primary storage and purchased a DD for archive storage. What I've done is create a Backup Copy Job that uses the DD as the repository with a GFS type retention. What I did was create a single DD Storage Unit for Veeam, to access, using DDBoost over FC. Called it veeam_dd_su01.
My question is, should I use the same Storage Unit (or mtree) for my DEV servers which will use the DD as primary backup storage? We don't need DEV on fast disks or instant recovery. Or should I create a second Storage Unit (or mtree)? Does it matter?