NetApp’s VTL: Best for Tape Libraries You Can Park Your Car In

We’ve been shipping our NearStore Virtual Tape Library (VTL) for about 18 months, and it’s interesting to dig into what customers actually like about it. When we first shipped, we had a good sense of the important benefits. We believed that virtual tape would help customers:

•  reduce their backup window
• reduce their restore time
• reduce the failure rate of restores

We were pretty close.

For instance, one of our most popular features is fast hardware-based compression, which lets the VTL run just as fast with compression as without. Without special compression hardware, you would still save space, but performance would be much lower. Saving money (by using less disk space) is always important, but meeting the backup window is so critical that compression without performance doesn’t cut it. (Stay tuned for VTL de-duplication, next year, which will further reduce storage costs.)

On the other hand, I’m surprised how important creating real tapes from the VTL has remained. Despite all the hoopla about disk-to-disk backups, eighty percent of VTL customers still rely on tape for some part of their process. One lesson here is how reluctant people are to eliminate processes in their “data protection path”. I expect that customers will be creating tapes and offsiting them for the next decade, so “work really well with my existing tape infrastructure” is a critical VTL requirement. What has changed is that customers go to tape much less often. With VTL, most customers go to tape weekly or less, instead of nightly, which lets them get much more mileage from their existing tape infrastructure.

The interaction between virtual tape and real tape is a fertile ground for innovation. The ability to support many virtual tapes at once, and then write real tapes later, means that you don’t have to schedule multiple jobs to the same physical tape drive. A problem with one thread doesn’t affect everything downstream, which makes a chaotic system much more deterministic. Staging backup data on disks also allows you to run tape drives at full speed -- avoiding the stop-starts that kill performance. This helps stretch existing tape infrastructure still further.

A final thing we’ve learned is that our VTL is so powerful that we tend  to compete best in large data centers. At one point we explained to our sales force, “You’re odds of winning are best if the customer has a tape library that you can park your car in.” We have introduced smaller products since then, but we need to come down even further to cover the whole market. We’re working on it.

 

Comments

[Kevin Graham]

Thanks for calling out the advantages of running drives at optimal speeds. Moving a modern drive close to its max throughput with a production workload isn't an easy task; this has been one of the spots a lot of VTL marketing has missed in the past.

With encryption now a native feature of the LTO4, is there any chance that the DataFort will begin to be relegated to key management with the data plane functionality (and control of drive functionality) becoming a "Decru personality license" on products such as the VTL?

What's really missing to deprecate-your-tape is network-enabled offsite archival. Everything I've seen available has been very small-scale and really only suited for sending a couple of tapes a week. Since the dot-com era managed storage ventures, the changes in regulatory requirements along with the prevalence of encryption would seem to open this up as a potential market with some industry standards.

(ObEnhancement: The NearStore VTL, of all the products in the space, really should be able to present itself as an NDMP server).

[Shibin Zhang]

This is an interesting topic. I did a little bit research on similar thing before. I even found a start up was looking for video compression experts to work on storage data compression products. My first impression was that those guys did not know how to do it. Video compression is lossy compression, but storage data compression has to be lossless.

I also noticed that Netapp is working hard on database and VM markets. Comparing to database and VM markets, which one do you think has greater potential? (I guess the answer will be: all of them have great potential).