Tape-Based Storage: Its Cheap, Its Fast, It Holds A Lot Of Data
Traditionally the lowest-cost medium for data storage, tape has taken a back seat in recent years to more costly optical media (CD-R, CD-RW, DVD-R) that can be more quickly accessed for information and are said to have a longer shelf life.
New advances in tape technology, however, are changing the way information technology (IT) departments think about storing their companies critical data on tape.
According to Rich Gadomski, director of marketing for Maxell Corporation of America, a tape manufacturer based in Fair Lawn, N.J., tape is still the cheapest medium in terms of cost per megabyte, and transfer rates of tape systemslong held to be one of their disadvantages"have improved dramatically.
"Storage has become a buzzword because of the Internet, e-mail and e-commerce," says Gadomski. "Its a pretty hot commodity right now."
When it comes to tape, Gadomski notes, DLT (digital linear tape), and "particularly DLT-IV" are the mainstay for storage in larger network and mainframe environments. DLT-IV tape cartridges hold up to 40 gigabytes (GB) of data, and up to 80GB if data compression software is used. This format has been around for about six years, starting out with cartridges that held 10GB (20GB compressed).
According to Gadomski, tape is the "ideal" storage medium for mainframe systems, storage area networks (SANs) and other network servers. "Its removable, which makes it good for archiving or disaster recovery," he explains. "You can take it to a remote site [for storage], as opposed to a fixed hard disk."
Just recently, SDLT-I (super-DLT) format tapes became available, offering users up to 110GB native and 220GB compressed, says Gadomski. (By comparison, read-only DVDs can store up to 17GB, while rewritable DVDs hold up to 9.4GB.) The SDLT-I cartridges are currently available from some drive manufacturers and will be shipped by Maxell this month or in July, he adds.
While shelf life seems to be one of the main issues with regard to long-term storage of data on tape, Gadomski maintains that "all of our newer tape products are rated at 30 years life span, under normal use conditions and not subjected to abuse." (Industry estimates for the life span of optical media range from 100 to 200 years.)
"Technically speaking," says Gadomski, "if you want to retain documents for legal reasons, its better stored on write-once products such as CD-R. DVD-R will also be applicable for long-term storage." Gadomski explains that for information that would be admissible in courts, media that cant be "written to" (re-recorded) are preferable. "Tape is ideal for backup and disaster recovery," he notes.
