Does Anyone Have Experience With Offsite Tape Library

Ekaj525

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PREDATAR Control23

IBM has it in their documentation that having a tape library at a different site than your TSM server is possible. Does anyone have any experience with this? Any cons besides networking issues? What networking protocols did you use? Did you use FC straight through or FCoE?
 
PREDATAR Control23

So in my environment I have the TSM server with a small TS3310 at the main site.
Offsite I have a TS3500 library greater than 5 miles away.
We are using straight FC. Keep in mind, depending on the LTO drive, you may need to look at the number of links you have available, or you will hit performance issues. Especially if other people start to hitch a ride on your links. Depending on how far away you are, you will need to invest in the right equipment to drive long haul optics. You'll want redundancy so you will need multiple routes in the street. You don't want both your fiber pairs running down Main street to get taken out by construction (happens more than you think!).

I have no experience with FCoE, and the few times I brought that up, my network team states 'Keep your fiber off my network'. Will state that our Ethernet network is running over the same fiber in the street as our FC is, so if you have extra pairs or waveleingths, it shouldn't be a problem to add on. Nothing against my network team, they just don't want to manage the SAN side of things. Their hands are full with day to day core routing and the likes.

So in short, yes you can do it. There is going to be cost involved, and depending on your resources the cost could be expensive. Last I knew, to drive our 8gb FC for 5 miles was 20k USD per laser. Plus the various interconnect fees for termination, and likely a whole bunch of other stuff that I am not privy too.

Biggest con is make sure you have enough capacity to utilize the number of tape drives.
If its a cold site, you will need to plan on visiting it to load cleaning tapes, scratch tapes. Monitoring the tape library also becomes important, make sure you have a way to remotely manage it.
My team and our infrastructure is great and I never have any issues communicating to my remote library. The issue I have is the performance. (See my various posts talking about performance). The expense can be...well...VERY high. I cannot stress this enough, if you don't have the budget to get the required infrastructure in place, don't do it. I don't have any equipment recommendations, but you'd likely want to go with the big name networking companies for SAN and Ethernet so you have that level of support. Don't use the cheap stuff.

Keep in mind, a single 8gb hba can drive two - to two and a half LTO6 drives at full speed, assuming the disk storage can keep up. Look at your tape drive specs, how hard can you push your storage and use that to help figure out how much capacity you will need, and then see if anyone else will be hitching a ride on your links!

I hope this helps. I know, there is a lot more to consider what I posted here, but my wish is it gets you thinking on the right track.
 
PREDATAR Control23

IBM has it in their documentation that having a tape library at a different site than your TSM server is possible. Does anyone have any experience with this? Any cons besides networking issues? What networking protocols did you use? Did you use FC straight through or FCoE?

It has been a while when I set one up. I'll be honest and this was still with TSM 5.x.

I had an environment wherein nodes (servers) where in Vancouver and Calgary. These 2 locations had local TSM servers but no Tape libraries. The Library was back in Toronto.

What I did is to setup server-to-server communication between Vancouver<>Toronto, and Calgary<>Toronto. This naturally mean plain TCP/IP communication between the sites. The nodes would backup to a stgpool in Toronto. The diskpool then empties to the tape pool.

Backup success will depend on number and size of files and how fast the links are.

This setup worked well for me.
 
PREDATAR Control23

Thank you for your post, the information is helpful. I should probably explain a little more what the end goal is. I am setting up a new TS4500 to place my TS3500, the new library will have TS1160 drives. This is for my primary site. The sites I am talking about will be strictly for DR. The DR server will be at a second site and the two tape drives will be mounted in a rack unit at a third site. Distance will be less than 5 miles. Daily change is like 5TB. Total data backed up around 200TB.
 
PREDATAR Control23

Thank you for your post, the information is helpful. I should probably explain a little more what the end goal is. I am setting up a new TS4500 to place my TS3500, the new library will have TS1160 drives. This is for my primary site. The sites I am talking about will be strictly for DR. The DR server will be at a second site and the two tape drives will be mounted in a rack unit at a third site. Distance will be less than 5 miles. Daily change is like 5TB. Total data backed up around 200TB.

Personally, I would not setup something like this even if the distance is less than 5 miles.

I am not a big fan of "unattended" devices - those that are not under any 'intelligent' control locally. There are other technical reasons for these.

One main technical reason that I don't like remotely linked devices is that there is limited or no data buffering that effectively slows down transfer speeds. Having a TSM server with a suitable disk stgpool in front of the tape drives at the third site assures me that I can transfer data faster and almost be certain that transfered data is correct. A TSM server can also compensate for network issues.

Now, why a third site just for the tape drives? Seems a little odd setup unless real estimate is an issue or operations is limited on the second site. If the latter is the case, why not have the DR TSM server at the third site?
 
PREDATAR Control23

Third site was decommissioned as a suitable server location. My third TSM server and old rack mount tape drives are still there. No disk, direct restore from tape to server. Site two is a colo and replacement for site three. No one thought about the impact to DR recovery by moving. After talking it over with the infrastructure team I think we might be moving the drives to site two for direct connect. Which I think is the best decision. The third TSM server will probably be retired once we are off the old hardware.
 
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