Some vendors say tape is dead (mostly in an effort to sell more disk products), but very few companies can back up data effectively without a tape library. In this product roundup, we discuss how tape libraries are used, how they're evolving, and what the competitive landscape looks like.
Tape libraries currently serve two important purposes: backup and archive, both of which can be enhanced by placing the library into a storage area network (SAN). Incorporated into a SAN, a tape library can be shared by several servers to backup data to tape.
Only very small companies can do without a tape library, according to Curtis Preston, vice president of service development, GlassHouse Technologies. But just about everybody else needs one. "Companies need the automation that tape libraries bring to backups."
According to Whatis.com, a tape library is a collection of magnetic tape cartridges and tape drives. An automated tape library is a hardware device that contains multiple tape drives for reading and writing data, access ports for entering and removing tapes and a robotic device for mounting and dismounting the tape cartridges without human intervention.
It's this "no human intervention" element that helps companies save money. Without tape libraries, IT administrators would be spending most of their time taking out old tapes and putting in new ones. "Ten years ago, when disk drives were in the megabytes and tapes were in the gigabytes, that worked," said Preston. "We could put a single tape in and back up the server to it without swapping tapes. Today, disk drives (or virtual drives in an array) are in the terabytes and tapes are in the hundreds of gigabytes. That means tape swapping. Without libraries, we're swapping tapes all night long."
Key vendors and products:
The big tape library vendors are as follow: StorageTek (Storage Technology Corp.), ADIC, Quantum Corp., Sony and Spectra Logic Corp. for larger libraries; and Qualstar Corp., Overland Storage, Inc., Breece Hill, Exabyte Corp. and Tandberg Data for small to medium libraries.
Most of the larger companies allow you to grow from several hundred slots to thousands of slots by putting two or more units next to each other and connecting them. Some of these scalability features have fallen to the SMB level, where smaller tape libraries can now expand from 20 slots to as high as 200 slots.
Innovations and trends:
One of the biggest innovations in the tape library industry right now is scalability. Expandable tape libraries from ADIC, Overland, Breece Hill and Quantum allow you to start small and expand to much larger capacities, but address the total unit as one library.
But how tape libraries expand differ depending on the vendor.
StorageTek, Quantum and Sony tend to use a monolithic unit with two connected tape libraries. By using "pass throughs," a company can buy another tape library when one library is full and the tapes are physically passed from one library to another using a pass-through port. Each library still has its own robot.
According to Preston, this is not a very efficient way to expand, mainly because you have to buy a whole new library and have two robots operating.
He said the more effective method is to do what ADIC and Spectra Logic do, which is take off the side of the first library, and bolt another cabinet to the side, and allow the first cabinet's robot to move into the second cabinet. "This method costs less and it's more efficient, because you're only using one robot and all the tape drives have access to the new slots immediately," Preston said.
Integration with Virtual Tape is another hot innovation. Virtual tape libraries (VTLs) are just disks that are configured to emulate tape. Preston highlighted FalconStor Software, ADIC and Sepaton Inc. as technical leaders in the VTL space because "they are excelling in VTLs that integrate best with tape in the backend."
Preston also pointed out that most tape libraries have handy Web-based management capabilities and phone-home reporting features, where the tape library alerts itself when there is a problem.
More from the Storage Media Group (SearchStorage.com and Storage magazine) on this topic:
StorageTek hammers out OEM deal with Permabit
StorageTek throws lifeline to Storability
IBM, ADIC swap patents
ADIC jumps on ILM bandwagon
Quantum leaps into LTO
Quantum readies WORM option for latest SDLT drives, media
Airline cuts sky high costs with VTL