Focus on: Midrange tape trends

LTO has captured the lion’s share of the midrange tape market, but users don’t buy based on market share.

By Dave Simpson

Although tape is increasingly sharing the backup burden with disk, tape is still the dominant media for backup-and-recovery operations as well as archive operations. But tape drive/library/media manufacturers are aware that they have to stay on pace with their capacity and performance road maps to maintain their place in the backup hierarchy. And, for the most part, they’re doing that.

In terms of trends in tape formats, LTO continues its rapid takeover of the open systems midrange market, which consists of the AIT/SAIT, DLT/SDLT, and LTO Ultrium formats. This market used to be referred to as “super drives” and is characterized by technologies with a capacity of 100GB per cartridge or more. This segment does not include low-end tape technologies such as Travan and DDS or high-end tape technologies geared to the mainframe market.

Looking at trends from the perspective of tape library shipments, LTO accounted for about 84% of all shipments last year and is expected to garner a commanding 88.3% share this year. That compares to a projected 8.3% market share for DLT/SDLT and a 3.4% share for AIT/SAIT, according to a report released this month by Freeman Reports (www.freemanreports.com). (See figure, below, for unit shipments and revenue figures for the open systems midrange tape library market.)

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However, end users don’t buy based on market share. Choosing the right tape technology for your backup/recovery or archiving applications requires weighing capacity, performance, and cost tradeoffs. And your choices are expanding because the next generation of SDLT began shipping last month.


Freeman Reports analyst Bob Abraham expects shipments of AIT/SAIT libraries to continue to decline, but at a slower rate because of the introduction of new generations of both AIT and SAIT. Debuting last year, AIT-4 has a transfer rate of 24MBps and a capacity of 200GB per cartridge. (See figure below for a comparison of capacities and transfer rates for all tape formats.)

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(Editor’s note: All capacities and transfer rates in this article are given in native [non-compressed] mode unless otherwise indicated. Compression is typically specified at a 2:1 ratio, thereby doubling capacity and transfer rate, although compression ratios depend on a number of factors.)

SAIT, which is based on helical scan technology, currently has a capacity of 500GB per cartridge and a transfer rate of 30MBps. However, the second generation of SAIT is due within the next few months, although final specs (cartridge capacity and data-transfer rate) were not available at press time.

“AIT and SAIT continue to be popular among the installed base of AIT users,” says Abraham. He notes that the key advantages of AIT are low cost per gigabyte and a small form factor. On the downside, AIT/SAIT has only one source (Sony) and rollouts of next-generation products have generally been slower than those of other formats such as LTO and SDLT-more than 24 months, compared to 18 to 24 months for competing technologies.


Although research firms such as Freeman Reports still refer to the high-end segment of the DLT market as Super DLT (SDLT), Quantum recently changed its product line nomenclature to reflect two subsegments of the technology: DLT-S (“Super”) and DLT-V (“Value”), which is characterized by lower cost/capacity/performance than DLT-S. Abraham notes that the DLT-V products are popular in entry-level servers and low-cost autoloaders. (Autoloaders are characterized as having a single tape drive and 10 or fewer cartridge slots.)

(For a hands-on lab review of the latest generation of DLT-V, or DLT-V4, see “Quantum redefines DLT ‘value,’ ” InfoStor, March 2006, p. 40. A review of the DLT-S4 will appear in the next issue of InfoStor.)

The DLT-S line is a replacement for DLT7000/8000, but has struggled against competition from LTO over the last few years. However, Quantum last month began shipments of the next generation of this technology-DLT-S4-which marks a departure in Quantum’s positioning of DLT technology. The company is now emphasizing the high-capacity advantages of the DLT-S product line, as opposed to data-transfer rate.

For example, DLT-S4 has a transfer rate of 60MBps, which falls short of LTO-3’s transfer rate of 80MBps. But DLT-S4 boasts a cartridge capacity of 800GB, compared to 400GB for LTO-3.

“Quantum is differentiating SDLT [DLT-S] from LTO by stressing its capacity advantages,” says Abraham. “This eliminates the head-to-head competition between SDLT and LTO that has plagued SDLT over the last five years.” Abraham says that the emphasis on high capacity fits in well with tape’s transition toward a primarily archival role, as opposed to online or nearline backup.

The DLT-S4 tape drives are available with 4Gbps Fibre Channel, Ultra320 SCSI, or Serial Attached SCSI (SAS) interfaces and are backward-read-compatible with SDLT 600 and SDLT 320. Pricing starts at $4,495 per drive and $100 per cartridge. The DLT-S4 drives are available as stand-alone units or in Quantum’s PX720 tape libraries.

In addition to DLT/SDLT, Quantum sells LTO drives and libraries, as well as devices based on the DAT, DDS, and Travan tape formats.


LTO is expected to retain the lion’s share of the midrange tape market going forward. Shipments of LTO-based tape libraries are expected to increase from 50,363 units last year to 55,488 units this year, with revenues rising slightly-from about $1.25 billion to $1.26 billion this year.

Manufacturers of LTO drives include Hewlett-Packard, IBM, and Quantum (via its 2004 acquisition of Certance); LTO media manufacturers include Fujifilm, Imation, Maxell, Sony, and TDK; and LTO library/autoloader vendors include ADIC, Breece Hill, Exabyte, Fujitsu, IBM, Overland Storage, Qualstar, Quantum, Spectra Logic, StorageTek/Sun, and Tandberg Data.

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LTO-3, the most recent version of LTO, has a cartridge capacity of 400GB and a data-transfer rate of 80MBps, which roughly translates into a backup rate of 576GB per hour in compressed mode. LTO-3 is read-compatible with LTO-1 and LTO-2 and is write-compatible with LTO-2. LTO drive manufacturers (Hewlett-Packard, IBM, and Quantum) have defined three more generations of LTO in their road map (see table), although delivery timetables are not available. (For more information on LTO, go to www.ultrium.com.)

General trends

Overall, unit shipments of midrange tape libraries declined about 2% last year, although Freeman Reports predicts a modest increase of 5% in unit shipments this year. Meanwhile, revenues in this market segment increased 16% last year, but are expected to decline about 1% this year.

The stagnation is due, in part, to the trend toward disk-to-disk (D2D) backup and recovery.

“D2D has negatively affected the tape market, although in most cases tape complements D2D backup and recovery,” says Abraham.

He notes that the other factor that has negatively impacted tape shipments and revenues is the rapid increase in tape cartridge capacities, which translates into fewer drives/libraries required by end users.

One bright spot for the midrange tape market is users’ increased need for write-once, read-many (WORM) capabilities, which is due, in part, to regulatory compliance requirements. The latest generations of midrange tape technologies (as well as half-inch tape cartridge technologies from vendors such as IBM and StorageTek) are available with WORM capabilities. However, Abraham estimates that less than 10% of the total tape cartridges shipped are used in WORM mode today.

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Tape libraries and autoloaders with fewer than 40 cartridges are by far the most popular configurations in terms of unit shipments, although units with 40 to 100 cartridges are expected to experience the most growth this year (see figure, above). Shipments of high-end libraries with more than 100 cartridges are expected to hold steady this year.

Although tape-based backup/recovery often gets dinged for being unreliable, that situation seems to be changing for the better. In a survey of InfoStor readers (conducted last year), more than three-fourths (75.7%) of the respondents reported backup failure rates of less than 10%, and 14.8% reported no backup failures.

When asked what the primary reasons for backup failures were, 26.8% cited media failure, and 16.1% indicated hardware failure.

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But the other 57.1% of the respondents cited factors that were not related to tape technology: user error (21.4%), software failures (19.6%), and network failures (16.1%). And 35.2% of the survey respondents planned to buy more tape over the next 12 months, while only 12% anticipated purchasing less tape (see figures, above).

Similarly, in an end-user survey conducted near the end of last year by Robert W. Baird & Co., 45% of the respondents expected to spend more on tape in 2006, while 25% anticipated less spending on tape, and the remaining 30% expected tape spending to remain about the same.

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In a survey conducted last year by the Enterprise Strategy Group (Tape Replacement Realities), 37% of the respondents said they were “very satisfied” with their enterprise-class tape libraries, 49% were “satisfied,” and only 4% were “dissatisfied.” However, those respondents also listed a number of challenges with their tape libraries (see figure, above).

Survey reveals backup-and-archive trends

By Thomas M. Coughlin and Farid Neema
A survey conducted by Peripheral Concepts and Coughlin Associates targeted IT organizations with a minimum of 1TB of raw disk capacity. More than 2,000 qualified respondents answered a screening survey, and a selected population of 135 IT administrators and managers answered the full survey. About 70% of the screening survey respondents were in the small to medium-sized business (SMB) category.

The resulting Backup and Archive User Perspective Report reveals trends in backup/recovery/archiving and the key issues that storage administrators face.


The two metrics IT organizations use to characterize recovery plans are recovery time objective (RTO) and recovery point objective (RPO). RTO is the time required to recover data, and RPO is the maximum time-window of data loss the business can afford. The number of companies in our survey population aiming at RTO and RPO of less than 20 minutes has doubled since our 2004 survey.

IT managers’ most-significant data-protection-related issues are time to restore, recovering from system failure, and recovering from disaster. The major impediments to acquiring the data protection that companies need are the following:

  • High cost
  • Fear of adding management complexity
  • Bandwidth costs
  • Staff shortages
  • Time to install

The window required to do a full backup has been decreasing steadily. In our most recent survey, 32% of the IT managers report that they require less than 60 minutes for a full backup, versus about 15% in 2004 (see figure, below).

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Archive and backup are often treated as one activity despite their different requirements. More than one-third of the surveyed companies do not differentiate backup from archiving, practically unchanged from the results of the 2004 survey.

A majority of the survey participants have a policy for destroying expired archived data. When asked what forces are driving their archiving requirements or policies, compliance with regulations ranked highest, followed by legal requirements and company policy.

IT managers say that the most-important archive attributes are high reliability, high capacity, and long-term retention. Write-once, read-many (WORM) capability, off-site transportability, and meeting regulatory compliance were less-important attributes (see figure, below).

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While 54% of the survey respondents archive specific applications today, 57% (about the same percentage as in 2004) currently have a policy to archive e-mails. This percentage will increase to 63% in the next year. In our 2006 survey, 22% of the companies have no plans for e-mail archiving and 15% “didn’t know.”

The ratio of online tape capacity to disk capacity averages about 1.5:1 today, compared to about 2:1 in 2004. Tape has the greatest percentage of use for archiving today-68%, compared to 75% in the 2004 survey, although disk is increasingly being used for archiving.

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When asked to list their major issues with the backup-and-archive process, 41% of the survey respondents cited “time to restore from backup,” followed by backup window, retrieval times, and personnel required (see figure, above).

Tom Coughlin is president of Coughlin Associates, and Farid Neema is president and senior analyst at Peripheral Concepts. For more information on the 2006 Backup and Archiving Report, visit www.periconcepts.com or www.tomcoughlin.com or www.tomcoughlin.com.

Recent tape-related product announcements

Quantum last month expanded its tape line with the introduction of the DLT-S4 tape drive, which offers increased capacity and throughput. The company also announced that it is placing its tape software products under the umbrella of its DLTSage brand.

The DLT-S4 provides a native capacity of 800GB (1.6TB compressed, assuming a 2:1 compression ratio) and a transfer rate of 60MBps (120MBps compressed). The DLT-S4 has backward-read-compatibility with SDLT 600 and SDLT 320. Interface options include 4Gbps Fibre Channel, Ultra320 SCSI, and Serial Attached SCSI (SAS). The media is referred to as DLTtape S4.

Pricing for the DLT-S4 tape drive starts at approximately $4,495, and the media is priced at about $100 per cartridge.

The DLT-S4 is targeted primarily at companies using tape as an archival medium, storing large quantities of data. The DLT-S4 is also designed for organizations that use disk-to-tape backup, characterized by storage-intensive applications that are growing rapidly, such as video and multimedia. Additionally, DLT-S4 targets companies with centrally managed backup architectures that are standardized on the SDLT format.

The DLT-S4 is available as a stand-alone tape drive, or integrated into Quantum’s PX720 tape library.

When the DLTSage data-protection software suite launched in 2002, Quantum focused on the management features of the product, including monitoring, diagnostics, and reporting tools to enable users to monitor the health of tape media and manage their backup environments. The DLT-S4 tape drive is the first product to offer the DLTSage tape security feature announced in December. This provides an electronic lock for the tape cartridge, which either prevents or allows access to data on the cartridge. Encryption at the drive level is planned for the second half of this year. In addition, the DLTIce write-once, read-many (WORM) feature that Quantum introduced 18 months ago on its SDLT 600 drive has been re-branded “DLTSage WORM.”

Targeting SMBs, Tandberg Data recently began shipping the 220LTO, a half-height, 5.25-inch LTO-1 Ultrium drive with a native capacity of 100GB and a native transfer rate of 16MBps, which roughly translates into a backup rate of 57.5GB per hour. Priced at less than $1,000, the drive includes an Ultra160 SCSI interface.

Exabyte’s VXA-172 Packet Drive and VXA-172 Packet Loader are based on the company’s 8mm VXA tape technology. The Packet Drive provides 172GB of compressed capacity (86GB native) and can be upgraded in the future to almost double that capacity via software updates, which Exabyte refers to as “capacity on demand.” The drive is priced at $699. Tape cartridges are available in two capacities: 86GB (at $15 per cartridge) and 172GB (at $29 per cartridge). The VXA-172 Packet Loader has 10 cartridge slots and a total capacity of 1.6TB, assuming 2:1 compression. The autoloader is priced at $1,599.

The capacity-on-demand software upgrade will be priced at about $349 for the drive and $599 for the autoloader. Both the VXA-172 drive and autoloader are available with Ultra2Wide SCSI interfaces, with Serial Attached SCSI (SAS) and FireWire options slated for later this year.

This article was originally published on April 01, 2006