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LTO cartridges include a built-in cartridge memory. This is an RF module with a non-volatile memory (4Kb); it provides a duplicate file log of cartridge data positioning and user specified information. An external reader allows immediate access to that information without having to insert the cartridge into a drive. A typical Ultrium cartridge costs approximately $137.
What's in store for LTO? IBM, Seagate, and Hewlett-Packard are committed to a four-generation LTO road map and a doubling of capacity and transfer rates with each new product.
In the fourth generation, Accelis capacity will be boosted to 200GB (native) with data transfer rates ranging between 80MB/s to 160MB/s (native). Access times are expected to be less than seven seconds. Ultrium capacities will increase to 800GB (native) with data transfer rates ranging between 80MB/s to 160MB/s (native).
Optical tape: The new kid on the block
- A new array write head architecture which yields a 32-channel head, facilitating high sustained data recording rates and high data storage density.
- An optical head system architecture providing simultaneous readback of the 32 channels without channel alignment issues; this provides for high sustained data transfer rates.
- A new cartridge design which incorporates extra wide short tape, reducing data access times.
What's in store for optical tape? O-Mass plans to introduce a new drive every 18 months spanning four generations, beginning with its initial product shipments. Each generation will double capacity and transfer rates resulting in a fourth generation capacity of 10TB (native) and a 1GB/s (native) transfer rate.
Knowing what tape technology to use is your job, but sometimes it's not always easy to cut through the marketing hype to make smart comparisons (see "How tape formats compare" below).
The 8mm market is dominated by AIT, which offers an excellent price performance offering for departmental backup and recovery applications. It also provides high density in tape library applications because of its small media size. Mammoth technology is good in these same areas, but the company was late to market, which enabled AIT to take the lead.
DLT technology works well in large tape library applications and in data backup applications, but isn't the best choice for applications such as HSM that require fast access to the first data block.
LTO technology offers the best combination of heavy-duty use and fast access to data at a reasonable price. LTO Accelis will be used primarily for single drive applications at the entry level.
Optical-assisted tape holds the promise of high capacities on a very robust media. However, with the price of disk storage dropping rapidly, it will have to be low enough to be an attractive alternative to existing options.
This was first published in July 2002