Linux Tape Device Emulation?

Tue Jan 17 07:15:40 PST 2006

> Annoying, but at least I can get around that by scheduling a tape 
> rotation once or twice daily from the noc staff at my colo provider.. 
> Though, if RMT performs just as well as local tape, then I might as well 
> just attach to my backup server, then.

RMT with an adequate blocksize is in the same ballpark, but local tape 
is going to give you the best speed.  If you have remote hands who can 
touch tapes every day, I'd stick with local tape.

> Is the speed on an LTO-1 comparable to the dlt-7000, 4 hours for 30GB 
> worth of data? This seems really slow.  We have the M450 so perhaps the 
> speed has improved somewhat?

I think it's probably comparable.  I don't have an M450 to try, and 
didn't have an LTO-1 until recently.  It's still expensive to open 
files, though, so I wouldn't look for a lot more than this.  Give it a try.

> Virtual Tape libraries are appealing. I'm thinking, however, that the 
> price point is bound to be just as prohibitive as a higher end backup 
> solution that supports NDMP like Veritas, or Legato currently is.

I also have a physical tape library (28-slot DLT-4000 thing), and after 
playing with it came to the conclusion that the big bucks you spend on 
Veritas are mostly about managing such a thing: talking to it, knowing 
what is on which tape, etc.  I have so far avoided needing it, but it's 
next in line.

> rather copy the data to a file server, then just copy the deltas (or 
> full images) over the wan to our other datacenters for off-sight every 
> night.

The WAN copy angle is where Data Domain looks good, btw, since it 
compresses first and only copies deltas.  If you pay for bandwidth, this 
can open up some options that aren't otherwise economically feasible.