Tale Of The Tape
The once-thriving storage tape business has been knocked out of the running as the media of choice for backing up data, but it is expected to remain the primary technology for use in long-term data archiving for the foreseeable future.
Disk-based arrays, optical drives and virtual tape libraries have pushed tape out of data centers and server closets as a way to do backups, and new cloud-based storage technologies are threatening to drive the final nails into the tape backup coffin.
Tape has received a bad reputation thanks to reliability issues, the impact on backup windows from slow read and write speeds, and stories about tapes getting lost. More importantly, with large backups, it is very difficult to do the kinds of tests that give customers peace of mind knowing that their data can be restored if needed.
However, when it comes to archiving data for years and decades, tape is not only maintaining its status as the storage medium of choice, it is actually seeing growth.
The main reason for this is the very low cost per GB of capacity of tape vs. that of disk and cloud storage. While disk-based storage is important for fast recovery of data, for mass quantities of data likely never to be accessed again, cost is a big factor.
Power consumption is also a factor for a similar reason because once data is written to tape, the tape will not consume power unless that data is restored or new data is written.
Furthermore, reliability is no longer an issue with tape thanks to new materials and recording technologies.
Long-term archiving and disaster recovery has become the focus of tape technology, said Michael Spindler, data protection practice manager at Datalink, a Chanhassen, Minn.-based solution provider.
Deduplication helps reduce the amount of data stored on disk or tape, Spindler said. ’But for long-term requirements, you can still store data on tape at an order of magnitude cheaper than on disk,’ he said.
For remote disaster recovery, customers are deduping data and then replicating it to the disaster recovery site, Spindler said. ’It used to be that only telecom customers did that because they were the only ones with the bandwidth,’ he said.
Virtual tape libraries, which are disk-based arrays configured specifically to emulate tape libraries, are good for fast backups and restores, said Joe Kadlec, vice president and senior partner at Consiliant Technologies, an Irvine, Calif.-based solution provider.
’But many customers want their data on tape somewhere to keep it safe,’ he said. ’They may replicate the data from one data center to another with tape using dedupe to increase performance.’
The tape library business is also getting a boost from customers looking to consolidate multiple smaller libraries into larger ones, Kadlec said.
’We have customers with older libraries look at the maintenance costs and think, ’Oh my God,’ ’ he said. ’We’re seeing customers get a new library with three-year maintenance contracts for little more than the cost of one year of maintenance for an existing library.’
The tape business has fallen off drastically except for large archives such as medical records where tape is mandated by government regulations, said Rolf Strasheim, director of client solutions at Peak UpTime, a Tulsa, Okla.-based solution provider.
’I don’t think anybody would say they’re happy with tape,’ Strasheim said. ’It’s like an accounting system: You just have it. The business is mainly driven by inertia. We don’t get some young buck opening a company and saying, ’We’ve got the fax machine and the phone system, now where’s the tape library?’
NEXT: Tape Libraries Changing, Too
Vendors are also seeing the move to larger tape libraries, although they indicate that autoloaders, which have a single tape drive and multiple slots, are making a minor comeback.
The low-end tape library business declined rapidly in 2008 and 2009, dragging down the entire business, said Matt Starr, CTO of Spectra Logic. However, with the focus on archiving, Spectra Logic is seeing growth once again, including in the autoloader market, Starr said.
Going forward, Starr said growth will continue thanks to the need to archive ever-growing amounts of data, especially fixed content such as videos and JPEG files, where deduplication technology has little impact on capacity.
Consolidation of tape libraries is causing a big uptick in the sales of large libraries, said Rob Clark, senior vice president of Quantum’s disk and tape business.
However, Clark said, Quantum recently has seen a surge in the midrange tape library market as well. ’I’m not sure why,’ he said. ’Maybe people have been waiting to purchase them.’
Clark also said he sees a future for tape in cloud computing because of the expense of cloud-based storage.
’Cloud providers charge a premium,’ he said. ’But they need to add tape on the back end as another tier. For cloud service providers, power and cooling are very expensive.’
For affordability and data portability, there is no real alternative to tape for long-term archiving, said Peri Grover, director of product marketing at Overland Storage.
’Once data is stored, 90 percent is never accessed again,’ Grover said. ’That’s a big waste of disk.’
The only real objection to tape today is speed, especially since data is stored sequentially, Grover said. ’But when it’s used for archiving, that’s not an issue,’ she said. ’You don’t need millisecond speed.’
Today’s tape market is almost exclusively centered the LTO format, with two enterprise-class formats from IBM and Oracle maintaining sales, albeit at very low levels.
LTO is by far the biggest-selling tape format in the market, having pushed its midrange competitors such as DDS/DAT, DLT, AIT, and others into near oblivion.
The LTO format, which originally was released in 2000, is now in its fifth generation. LTO-5 cartridges natively feature 1.5 TB of capacity and a throughput of up to 140 MBps, or 3.0 TB capacity and up to 280 MBps throughput at 2:1 compression. That is about double the capacity and throughput of LTO-4.
While further development of other midrange tape formats is not expected, the consortium of vendors that develop the LTO format have a road map which includes at least three more generations, giving the format a lifetime extending through at least 2018. The last currently planned generation, LTO-8, is slated to feature native capacity of 12.8 TB and throughput of up to 472 MBps, or 32 TB of capacity and up to 1,180 MBps, when compression is used.
Quantum’s Clark, who is a board member of the LTO Consortium, said the LTO road map is solid, and that there are even technologies that may help extend it. ’The original LTO team did a really good job of laying out the road map,’ Clark said.
In addition to capacity and throughput, LTO has seen continued development of other features. WORM (write once, read many) technology for configuring tapes to prevent overwriting or deleting of data was introduced with LTO-3, while LTO-4 introduced encryption technology to prevent unauthorized access of data from a tape.
The biggest technological advance introduced with LTO-5 was partitioning and the Linear Tape File System, or LTFS.
NEXT: New Technologies, New Formats To Come
Partitioning segments an LTO-5 tape cartridge into two partitions. LTFS uses this feature to place metadata, or index information, related to the content of the tape on partition 1, and the actual data on partition 2. This allows users to view the contents of the tape as if viewing a hard drive, and do drag-and-drop operations to the data in Linux, Mac OS, and Windows environments without the need to sequentially read the entire tape.
The primary benefits of LTFS include the ability to easily share data on the tape between multiple storage units, and to break the tie between the data and its originating application so that data can be more readily accessed in the future.
For very high-end enterprise requirements, there are currently two tape formats available.
The first is Oracle’s T10000 series of drives, which were inherited by the company when it acquired Sun Microsystems last year.
Oracle in January introduced the newest version of that tape drive family, the StorageTek T10000C. It features a native capacity of 5 TB and a native throughput of 240 MBp, both of which are considerably more powerful than the other tape formats on the market.
With the T10000C, Oracle claims to be able to build the first storage solution to scale to up to one exabtye of capacity, using 2:1 compression. An exabyte is equivalent to 1,000 petabytes. That is about 17 times the capacity of an IBM tape library using IBM’s TS1130 drives, and 30 times the capacity an EMC disk-based backup solution, Oracle said.
Oracle has already been talking to customers about a road map for its T10000 series drives, with some reports predicting the eventual development of a tape cartridge which can hold up to 20 TB.
The second enterprise-class tape format is IBM’s Jaguar family. The current model is the TS1130, which offers a native capacity of 1 TB per cartridge and a native throughput of 160 MBps. It started shipping in 2008.
Reports from various sources say that IBM will unveil the next generation of the Jaguar tape family in 2011. That new tape drive, which will probably be known as the TS1140, is expected to have a native capacity of 2 TB and a throughput speed of about 240 MBps.
Not counting the very high-end enterprise Oracle and IBM tape market, where drive sales have never been high, overall sales of tape cartridges are slowly dropping, with the exception of the recently introduced LTO-5 models.
The Santa Clara Consulting Group, a Santa Clara, Calif.-based research firm, reported in February that total midrange tape cartridge sales in the fourth quarter of 2010 reached $209 million, down about 8 percent from the industry’s sales of $228 million in the fourth quarter of 2009.
The total number of midrange tape cartridges sold worldwide reached 7.7 million during the quarter, down 9 percent compared to the 8.5 million cartridges sold the year before.
However, 6.4 million of those cartridges sold were LTO types, with LTO-5 and LTO-4 accounting for 58 percent of the total LTO cartridge sales, the Santa Clara Consulting Group reported. Sales of all other midrange formats, including DDS/DAT, DLT, AIT, QIC and 8mm, were significantly down in 2010 compared to 2009.