>> On Mon, 17 Nov 2008 11:09:55 -0500, Paul Zarnowski <[EMAIL PROTECTED]> said:
> We are just in the process of creating copy volumes which we intend > to relocate to an off-site library in a few months. I want to make certain I'm responding to this correctly; I've been talking about remote virtual volumes. You appear to be discussing local volumes which you intend to physically transport, and then contact via virtualized fiber. If I've understood correctly, I think that your DR library is only "remote" in the meat world. You've got rmt devices on the local box which terminate in physical tape drives "somewhere". They're different from the drives you deem "local" only in performance. If I get your aim, you are attempting to have TSM treat the 'remote' volumes as though they are offline (in the Vault) and build new replacement volumes. You may be able to hornswoggle TSM into doing this by manually setting State and Location on a bunch of volumes. But I'm going to claim you don't want to do this, and the bandwidth utilization is in fact the optimal solution. The alternative, building new volumes, is going to waste a -lot- of local tape time. Each offsite reclamation process you go through, you're going to (to a good appoximation) mount every single primary tape in your library. Calculate mount delay * nvols as an absolute -floor- of wasted tape hours per reclamation attempt. And then your access is far from optimal. Lots of seek-read -- seek-read. My offsite reclamation runs persist for days and days. As an alternative, -you- have the option of seeking along one physical volume, feeding another one. If you get the pipe right, you could almost certainly maintain > 40M/s on even a single Gb channel. It's duplex, remember... It would certainly be nice to have something SAN optimized, so you could do a direct tape-to-tape copy with the whole data channel Over There. I wonder if that's in the works anywhere... - Allen S. Rout
