Feature

Cutting through the tape maze

Ezine

This article can also be found in the Premium Editorial Download "Storage magazine: Overview of top tape backup options for midrange systems and networking segments."

Download it now to read this article plus other related content.

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


Optical tape highlights

    Requires Free Membership to View


TANDBERG/
O-MASS
CAPACITY
(NATIVE)
TRANSFER
RATE
(NATIVE)
FORM
FACTOR
APPROX.
PRICE*
Optical assisted* 600GB 24MB 5.25" N/A
*Scheduled for Q4 of 2003.
Magneto-optical assisted tape technology is coming from Tandberg Data/O-Mass. The first version of these tape drives will offer 600GB (native) storage capacity at a 64MB/s (native) data transfer rate. Average access time is said to be only 3.5 seconds. The enabling technologies for this new family of drives and media center around three key areas:
  • 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.
The drive's servo tracking and crosstalk decoding techniques do not require the use of preformatted media, reducing the cost of the media itself. Target price for media is $0.1/GB. The cartridge envelope is form factor compatible with existing tape cartridges, thereby making for easy integration into current tape automation architectures. The Tandberg Data/O-Mass drive and media - in combination with high performance robotics - can provide a viable alternative to disk farms. The first drives are expected to begin shipping in Q4 2003.

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.

Decisions, decisions
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.


How tape formats compare
NETWORK COMPONENT AIT-3 MAMMOTH-2 SDLT 220 LTO ACCELIS** LTO ULTRIUM* O-MASS**
Capacity native/Comp 100GB/260GB 60GB/150GB 110GB/220GB 25GB/50GB 100GB/200GB 600GB/N/AGB
Transfer rate native/Compressed (per sec) 12MB/31.2MB 12MB/30MB 11MB/22MB 20MB/40MB 20MB/40MB 64MB/N/AMB
Recording method HELICAL SCAN HELICAL SCAN LINEAR LINEAR LINEAR LINEAR
Interface SCSI SCSI/FC SCSI SCSI SCSI SCSI/FC
MTBF (hrs) 400,000 300,000 250,000 250,000 250,000 N/A
Head life (hrs) 50,000 50,000 30,000 N/A 30,000 N/A
Form factor 3.5" 5.25" 5.25" 5.25" 5.25" 5.25"
Media life (passes) 30,000 20,000 1,000,000 N/A 25,000 N/A
Backward compatible YES YES YES NEW PRODUCT NEW PRODUCT NEW PRODUCT
Access time 27 SEC 60 SEC 70 SEC <10 SEC 65 SEC 3.5 SEC
*LTO specs per Seagate removable storage solutions Viper 200 drives; **drives still under development. All specs not yet available.

This was first published in July 2002

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: