Data Domain vs. Protectier

Where I am currently employed we are looking to replace our 3592 based library with a deduplication solution. Currently the higher ups are leaning towards IBM ProtecTIER without having thoroughly investigated any other solutions. Having previously used Data Domain solutions at my previous employ I was somewhat concerned that the ProtecTIER solution would be a bad fit for our environment. I have had some run ins with people who have used IBM's ProtecTIER solution and when compared to those who have used Data Domain (including myself) you immediately see the difference in how they talk about the two products. So I was hoping to find a good write-up showing in-depth details comparing the two solutions and it took a blogger like me to provide a great comparison.  If you would like a good overview of how Data Domain and ProtecTIER stack up against one another in technology and performance check out the following link. It's very informative and solidifies why I would prefer using Data Domain.

Deduplication: Data Domain Vs. ProtecTIER Performance

One item that was not covered was the NFS capabilities of both. While I used VTL functionality with Data Domain, I was a HUGE NFS proponent. You can save a lot of money over a TSM TDP + LAN-Free solution using NFS with 10Gb Ethernet for your DB backups  (since IBM's licensing costs are still questionable). When I was first exploring ProtecTIER they did not yet have NFS capabilities, so I'd like to see a NFS performance comparison between the two products.

TSM's VTL DeDupe Reclaim Problem

So a friend of mine sent me this link to an article from Scott Waterhouse's "The Backup Blog" that discusses a known issue with TSM not reclaiming VTL tapes when dedupe is in use. I would recommend you check it out if you are using dedupe in your environment since it looks like it affects TSM no matter what dedupe product is in use when you use it with a Virtual Tape Library. The problem is solved with release 5.5.2 or higher.

SpectraLogic Library Review

We recently acquired a Spectra Logic T950 library for one of our data centers and I thought I'd let you all know how it's been performing. Since I was with IBM previously my only experience was with STK's (which we were trying to push out the customers door ASAP) and IBM hardware. I can say I was no fan of the STK L700 and being an IBM'er at the time I touted the 3584 and 3494's like they walked on water (they don't). We frequently had to have maintenance on our IBM libraries. Was it due to the fact we were collocating over 2500 clients and mounts were through the roof? Probably!

The data center I worked at with IBM had a secondary library room that housed the 8 libraries (some were for mainframes) and tape shelves. The room was running out of floor space to accommodate another library or expansions to existing ones. This is where SpectraLogic has IBM and the competition beat, hands down. A single T950 frame can house up to 24 drives and a max of 950 tapes with a frame H 78.77 in, W 30.63 in, D 43.21 in (H 200.1 cm, W 77.8 cm, D 109.8 cm). That's a little taller but less deep than an IBM TS3500 frame at 70.9"H x 30.8"W x 47.7"D (1800 mm x 782 mm x 1212 mm), with the IBM L frame handling a max of only 12 drives and 287 tapes.

How does SpectraLogic get such great density? They go vertical with a twist. SpectraLogic libraries use "TeraPacks" that are 10 tape chassis that load the tapes so the barcode are vertical not horizontal like IBM and most other libraries. When the library needs a tape its robot removes the TeraPack and then the gripper mechanism grabs the tape. I can hardly tell if it adds more than a second or two to the mount time, but even if it does the density gain negates the ever so slightly increased mount time.

I could go on an on and mention every little thing that I like about this library, but one of the coolest features is the ability to add SATA RXT portable RAID media, making the T950 VTL capable. The RXT media (which stands for RAID eXchangeable TeraPack) fits in the SpectraLogic half inch tape drive openings and is composed of multiple SATA disks sealed in a enclosure capable of taking rugged handling with built in shock dampening technology. The TeraPacks range in size from 2TB to 1TB, but I'm sure you will see larger sizes in the very near future. The RXT media is compatible with all major backup applications and operating systems.

The final item that sealed the deal was of course price. This library came in at a great price point, lower than IBM and Sun by quite a bit. This, added up with all the other features/benefits it offers in expandability, made it a win/win. "So, how has it performed?" You ask. Well, so far it has performed above my expectations. I have shed my IBM favoritism and seen it for what it was "stubbornness". I would highly recommend considering SpectraLogic the next time you seek to buy new or refresh old equipment. They definitely have the features everyone is looking for available in their libraries, and with data center space at a premium you can count on the T950 to give you the capacity you need in less space than competing libraries.

***UPDATE***
The mount time is a a lit more excessive than thought. Because of the TeraPack having to be removed, then the tape grabbed and placed in the drive, then the terapack replaced; the mount times are quite a bit longer when you have a VERY busy queue. I think SpectraLogic needs to speed this process up somehow. I must say if they can speed it up the overall library density is great. It would be cool if there was some way they could utilize a tool that grouped all scratch together and tapes that are most frequently mounted. Almost like a tape slot reclamation. It might speed things along when say 5 systems are all waiting for scratch. I need to research this a little more. I'll see if I can get feedback from SpectraLogic.