ADSM-L

Re: [ADSM-L] RMAN direct to NFS

2012-07-10 20:19:01
Subject: Re: [ADSM-L] RMAN direct to NFS
From: Nick Laflamme <dplaflamme AT GMAIL DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Tue, 10 Jul 2012 19:10:47 -0500
This is more about VTLs than TSM, but I have a couple of questions, influenced 
by my shop's experience with VTLs.

1) When you say "40 VTLs," I presume that's on far fewer frames, that you're 
using several virtual libraries on each ProtecTier or whatever you're using?
2) I see that as 128 tape drives per library. Do you ever use that many, or is 
this just a "because we could" situation? (We use 48 per library, and that may 
be overkill, but we're on EMC hardware, not IBM, so the performance curves may 
be different.)
3) Do I read 1) and 4) to mean that you're sharing VTLs among TSM servers? Why, 
man, why? Can't you give each TSM server its own VTL and be done with it? Or 
are you counting storage agents as TSM instances? 

I don't know if we'd have gone with VTLs if we were architecting this from 
scratch, but as we went from tape-based to virtual technology, the VTL 
interfaces made the transition logically simpler, and it appeased the one team 
member who has an irrational hatred of NFS. We're now under pressure to adopt a 
new reference architecture that is NFS based, not VTL based. I'm skeptical 
about that will work, but because we're changing everything except the fact 
that we're still a TSM shop, if it doesn't go well, everyone will have a chance 
to blame someone else for any problems. 

Now that I think about it, I have no idea how many paths we have defined to all 
of our VTLs on all of our DataDomains. It might be 10,000 paths ultimately, but 
when you define them a few hundred at a time, or fewer, it's not so 
overwhelming! 

Nick


On Jul 10, 2012, at 12:29 PM, Hart, Charles A wrote:

> The IBM one, the reason I said overhead and complexity 
> 
> 1) We have 40 VTL's for 
> 2) 5120 Configured Vtape Drives 
> 3) More than 10,000 TSM Tape Drive Paths 
> 4) 100 TSM Instances that share all the above
> 
> It would "seem" that if we used a VTL that has NFS we would still have
> 40 Devices but not he 15K objets to manage (tape Drives and paths)
> 
> Regards, 
> 
> Charles