Tape advances in capacities, transfer rates

Posted on August 01, 2006

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Tape’s role may be shifting from backup and recovery to archiving, but that hasn’t stalled technology innovations.

By Mark Ferelli

Tape is part of a rare group of IT technologies that have lived well beyond expectations. The mainframe was said to have died in the 1980s, yet is still with us today. OpenVMS was pronounced dead in the 1990s, but the operating system still has millions of users worldwide. The demise of tape has been discussed since the late 1960s, yet it’s still used in most IT organizations.

However, tape’s role is evolving. Historically, tape has been used primarily for backing up and recovering data stored on servers. More and more, however, tape is being used primarily as an archival solution for long-term data retention.

For those who do not manage storage on a regular basis, it would be tempting to equate backup and archival. But there are fundamental differences between the two applications.

Backups are point-in-time copies of not only data files, but also operating systems and applications software. Backups are designed for a comparatively short service life-until the next incremental or full backup. The primary purpose of a backup is to secure data against hardware failure or catastrophic loss. It is a disaster-recovery and business continuity tool.

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An archive volume, on the other hand, is not a copy of a data object. It is a file or record that has been migrated from online primary storage to a long-term repository, typically tape. Archives are designed for long-term retention, typically measured in years. And the purpose of an archive is cost-effective data preservation for support of corporate decision-making, litigation, and regulatory compliance.

Corporate decision support, litigation support, and regulatory compliance demands make up active elements of business operations. Therefore, considering an archive as a “file-and-forget” kind of digital records boneyard would be a serious mistake. Some records may be less frequently used, but they must be searchable and available without stretching IT budgets. Tape is the preferred technology for archiving because it still has a per-megabyte cost advantage over disk, as well as long media life.

Tape improvements

Tape vendors continue to make improvements, most notably in performance and capacity. “As disk capacities and speeds increase, so must tape capacities and speeds,” says tape industry veteran Juan Rodriguez, currently chairman and CTO at Exabyte.

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In addition to capacity and speed, other business requirements are driving innovations in tape technology. Dave Kenyon, senior director of tape product marketing at Sun (which acquired StorageTek), notes that the need for security in removable media, as well as encryption, is driving interest in tape. Write-once, read-many (WORM) functionality is also driving interest in tape, with regulatory requirements demanding more and more protection of data. The first tape makers responding to the requirement for WORM functionality were Sony with its AIT drives and Quantum with its DLT drives and DLTSage software, as well as IBM and StorageTek at the high-end.

Users have a wide variety of tape formats to choose from (see figure on p. 18), but in the midrange tape market (the fastest-growing segment of the overall market), the leader is the LTO format (see figure below). LTO is currently in its third generation, and LTO-3 drives, libraries, and media have been available for more than six quarters.

IBM’s Bruce Master, a spokesperson for the LTO Consortium, shares some features of the upcoming LTO-4 format: “Cartridge capacity for Generation 4 will be 800GB native [uncompressed], with a transfer rate up to 120MBps in native mode. Like LTO-3, LTO-4 will be WORM-capable. But Generation 4 will be the first to write encrypted data to cartridges; AES 256 encryption will be on board.” (For an LTO road map, see table, above.)

Tape targets SMBs

New LTO generations emerge approximately every two years. But earlier generations still show vitality, with new features added for new markets. For example, LTO licensee Tandberg is shipping a half-height LTO-1 tape drive designed primarily for the small to medium-sized business (SMB) market. The drives include a variety of features sometimes associated with higher-end, higher-cost drives, such as patented algorithms to provide faster file retrieval; pre-programmed self-diagnostics; a media management package that tracks read/write performance and detects defective or worn media; an advanced adaptive PRML read channel; and a gripper technology that locks the tape pin for a secure latch.

Earlier this summer, Tandberg began shipments of an autoloader based on the half-height LTO-1 drives. The 1U StorageLoader LTO-1 is priced at less than $3,000 and provides up to 800GB (1.6TB compressed) of capacity and a transfer rate of 32MBps.

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To reduce total cost of ownership (TCO), all components are field-replaceable, and maintenance and system monitoring can be performed remotely through Web browsers.

Tandberg’s emphasis on the SMB market is representative of most midrange tape drive vendors.

“Although no one is ignoring the high-end,” says Bob Abraham, president of the Freeman Reports tape market research firm, “the midrange tape makers are emphasizing the SMB space because it represents a good potential revenue stream.” Abraham points out that Sony’s AIT-1 and AIT-2 are particularly well-priced for the SMB market, and that these older formats still represent growth opportunity.

Most recently, Sony announced the next generation of AIT technology (see “Sony announces AIT-5,” below).

Likewise, Exabyte’s VXA tape format has always been focused on the SMB space, and Exabyte supports the channel with VXA-based autoloaders. (Exabyte’s OEMs include vendors such as IBM and Fujitsu-Siemens.)

Quantum’s DLT-V (“Value”) tape drives have also been strong players in the SMB market.

(For a hands-on review of one of Quantum’s more-recent introductions, see “DLT-S4 reveals ‘super-tape’ paradox,” InfoStor, May 2006, p. 34.)

All of these tape formats target the low-end SMB market, often at sub-$1,000 price points, and all are challenging the incumbent in the low-end SMB space: DDS tape. Each format has made some inroads, but none has displaced the popular legacy format.

“Disk-as-tape”

In an interesting new twist in the tape market, Imation is embedding Serial ATA (SATA) hard disk drives in an LTO Ultrium-compatible tape cartridge shell. The removable “disk-as-tape” Odyssey cartridge contains a 2.5-inch SATA drive, and the Odyssey docking station fits into any 3.5-inch drive bay, creating a solution that enables efficient, low-cost backup.

The Odyssey removable hard disk drive (RHDD) can be used with any Windows system and most storage management software packages.

Key benefits of Imation’s Odyssey include the following:

Cartridge reliability and shock resistance: The cartridge was designed to withstand high shock forces by adding protection in especially vulnerable areas;

Connector reliability: The Odyssey connector technology is rated for up to one million insertions;

Integrated electrostatic discharge (ESD) protection: The cartridge incorporates ESD protection into the cartridge material, which provides a means to minimize static buildup and safely dissipate static charges caused by media cartridge handling. Because hard disk drives contain sensitive electronic components, excessive static build-up and subsequent static discharge can lead to data loss; and

Soft-load mechanism: The Odyssey cartridge features a soft-load mechanism typically associated with higher-duty-cycle products, which eliminates excessive shock and vibration during loading and unloading.

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An implementation of Odyssey, known as Ulysses, is offered by Qualstar in its automation products. “Ulysses represents a significant addition to users’ tape storage options,” says William P. Gervais, Qualstar’s president. “Combining the cost and density advantages of tape libraries with the high-speed access time and media life of disk changes the storage landscape.” 

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Qualstar integrates Ulysses technology in its RLS-8216H and 8404H libraries, and users can combine LTO tape drives with Ulysses emulators in those library models.

Tape media advances

Not all of the advances in the tape market are at the drive, or library, level. (For more information on trends in the tape library market, see “Focus on: Midrange tape trends,” InfoStor, April 2006, p. 16.) Media manufacturers are also pushing tape technology forward.

Fuji Photo Film, for example, produces media for DLT and LTO tape drives. Although the media for LTO-1, LTO-2, and LTO-3 and DLT4 are based on Fuji’s ATOMM technology, upcoming LTO-4 and SDLT media will leverage the more recently introduced Nanocubic formulation, according to Rich Godomski, VP of marketing in Fuji’s recording media division.

Introduced in 1992, ATOMM is a double-coating technology. A lower, non-magnetic layer and a very thin magnetic coating are simultaneously applied to the basefilm. The manufacturing process produces a double-layer tape with lubricant in the lower layer. The very thin magnetic coating allows high density and low error rates.

Nanocubic technology was introduced more recently. Nanocubic combines an advanced deposition procedure that allows a 5x thinner coating and a new ferromagnetic particle material. Fuji developed two unique particles: acicular ferromagnetic alloy and tabular ferromagnetic hexagonal barium ferrite.

Imation, another tape media manufacturer, is also focusing on density and transfer rate. Imation’s most recent move was a joint venture with Sun (StorageTek) to develop advancements for the high-end 9840 tape format.

The planned fourth-generation T9840D will increase the native capacity of the cartridges to 75GB while maintaining the fast access and reliability that are hallmarks of 9840 technology, according to Subodh Kulkami, vice president of R&D at Imation. The T9840D enterprise tape drive leverages existing 9840 media. Customers will be able to protect their investment and extend their current media life with backward-read-compatibility to any 9840 media version.

Furthermore, the T9840D will include device-level encryption for written cartridges.

Complementing the drive technology, which is expected in 2007, the 9840 half-inch tape cartridge will feature the following:

An internal tape path design that improves data integrity and access time by managing tape movement completely within the cartridge;

A mid-point dual-hub design that has the ability to start searches from the middle of the tape, providing faster access to data;

An advanced, factory-written servo pattern that enables precise read-write performance for higher reliability; and

A new baseplate design that enhances cartridge stability and enables precise alignment between head and tape to ensure reliable data reading and writing.

Media manufacturer Hitachi Maxell Ltd. recently announced that the company will begin offering branded DLTtape S4 media. Maxell jointly developed the media with Quantum to support the data recording requirements of Quantum’s DLT-S4 tape drives.

The DLTtape S4 has a native capacity of 800GB (1.6TB with 2:1 compression) and a native transfer rate of 60MBps (120MBps with compression). Maxell’s DLTtape S4 media leverages Quantum’s DLTSage WORM capability for meeting legal and regulatory compliance requirements and DLTSage security features for preventing unauthorized access to data.

Maxell’s DLTtape S4 media is based on the company’s NeoSMART, which is a convergence of technologies that support higher-reliability recording and data recovery at the track and bit densities of DLT-S4 and future generations. NeoSMART’s improved magnetic particles, new coating, and dispersion technologies are designed to support future tape cartridge capacities beyond 1TB. A key component of NeoSMART is Maxell’s Nano Composite Advanced Particles (NanoCAP) technology, which could potentially support native capacities in the tens-of-terabytes range.

The latest advances in Sony’s tape media are apparent in the fifth generation of its AIT products, which are based on Advanced Metal Evaporated (AME) III technology (see “Sony announces AIT-5,” above). AME III accounts for the areal density of AIT-5, as well as the durability. AME III employs a new method for applying the magnetic layer to the tape, an enforced coating layer, and a new lubricant for more-stable operation.

AME III media achieves high output and low noise through an improved metal evaporated method of manufacturing, which results in smaller magnetic particles and a smoother tape that minimizes the spacing loss between the magnetic head and magnetic layer.

Conclusion

Tape technology is becoming increasingly important in the archival segment of data protection. There is also a trend toward low-cost, full-featured tape drives designed for SMBs. And tape is even being used as the enabling technology for its primary competitor-hard disk drives.

With all this activity, it’s clear that tape technology will persist well into the future.

Mark Ferelli is a freelance writer. He can be contacted at mcferelli@yahoo.com.


Sony announces AIT-5

Earlier this summer, Sony announced the fifth generation of its Advanced Intelligent Tape (AIT) technology. AIT-5 packs 400GB per cartridge uncompressed (or 1.04TB assuming 2.6:1 compression). That’s twice the capacity of AIT-4 cartridges. However, the native transfer rate remains the same as AIT-4 at a maximum of 24MBps (or 225GB per hour with 2.6:1 compression).

“AIT-5 represents a re-positioning and a change in direction for AIT,” says Bob Abraham, president of the Freeman Reports research firm. “Rather than try to continue doubling the transfer rate, Sony has stepped away from the LTO-SuperDLT war-which is a smart move.”

A number of Sony’s OEM partners have pledged support for the AIT-5 format, including Cybernetics, Qualstar, and Spectra Logic.

OEM evaluation unit shipments began last month, with volume shipments and end-user availability expected in October.

Michael Nixon, Sony’s senior manager of OEM products, says that AIT-5 will resolve the incompatibility problems that plagued AIT-4. For example, AIT-5 is read/write-compatible with previous generations such as AIT-4, AIT-3Ex, and AIT-3. In contrast, AIT-4 drives broke the backward-compatibility chain and were only read/write-compatible with AIT-3Ex media.

AIT-5 is based on many of the standard AIT technologies, such as an 8mm tape format with helical scan recording, a 3.5-inch drive form factor, dynamic tracking, Advanced Metal Evaporated (AME) media, a Remote-Memory-In-Cassette (R-MIC) chip, and support for write-once, read-many (WORM) functionality, which prevents overwriting, altering, or erasing data. However, the AIT-5 format marks the first time Sony has used magneto-resistive (MR) heads in its tape streamer products. MR heads enable the higher capacity of AIT-5.

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“AIT is a new technology platform, as opposed to an evolutionary step, with new media and head technology,” says Freeman Reports’ Abraham, “which will make it relatively easy for Sony to move to the next generation of AIT.” Sony’s road map currently includes a sixth generation-AIT-6-at a native capacity of 800GB per cartridge.

AIT-5 drives are expected to initially be available with SCSI interfaces, with support for other interfaces to follow.

-Dave Simpson


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