I am currently integrating a NetBackup Appliance 5220, and I am now detailing the SAN configuration. The intended use is to zone the the NBU appliance to the same LUNs as the ESX hosts and thus leveraging the SAN transport mode to pull the backups over Fibre Channel.
I have configured this in another vendor's backup solution and I'm fairly confident I can make it work.
However, this appliance already has a tape library connected via FC, and as such one of two available FC ports is used as the tape out port.
From reading the documentation, Symantec suggests to only use an FC port in one mode, FT SAN client (which I am not intending to use), replication between appliances (not currently in the scope, I only have one appliance although that might change), VMware integration (my intended use) and tape out (what I already am using).
I also read that on my current release, 2.6.0.2, multipathing to SAN LUNs is supported. I cant' find any device specific details, in my case it is an HP 3Par 7400 array.
However, if the suggestion is that I reserve one port for tape out, a consequence would be that I can only use one remaining port as the initiator to connect to the VMware datastores. Not really multipath, although this single initiator could still be spread across several target ports in the array I suppose.
Also, I, as well as the VMware people, are a bit apprehensive about presenting datastore LUNs to a third party host which is running Linux. Are we absolutely sure nothing will ever happen in the appliance, causing it to go nuts and overwrite data? In another environment I could present the LUNs as read-only to the backup host on the array level, thus eliminating this fear. I am not sure the 3Par array has this capability though.
Comments are appreciated.