RAM | Reseller Advocate Magazine: Issue 74

By Chris Angelini

Backup is a given nowadays. The real question is whether your customers back up to disk or keep alive the aging benefits of tape technology. Obviously, the answer is going to depend on who you talk to and what they’re doing. An SMB saving files from a few workstations might be able to make do with on-site hard drive-based backup. The only real worry there is a risk of loss due to natural disaster or theft. On the other hand, businesses that need to maintain records for 20 years are looking for storage that’s both easy to pop onto a shelf and durable enough to outlast the deteriorating effects of time. Tape might not be sexy, but it works well in that situation.

The purpose of tape is backup and archiving, plain and simple. In fact, because tape has historically enjoyed the best capacity-to-cost ratio, it was easily the most popular medium for storing critical information. Admittedly, the technology’s glaring disadvantages have nudged it out of favor in the past few years. For instance, magnetic tape is a sequential access medium, so it can read and write data at a respectable rate. But when a customer needs to pull individual files from backup, performance suffers. It’s also hard to argue in favor of tape’s price advantage now that nearline SATA hard drives are so affordable.

Is there still a place for tape in the SMB environment or should you be selling the virtues of disk-based storage instead? According to Mike Sparkes, product manager of storage products manufacturer Quantum, the answer still depends on your customer’s application, though there’s no denying the demand for tape has most certainly fallen off in favor of disk.

“It’s quite true,” says Sparkes, “that the core market for tape is much less than it once was because the core market for disk-based storage is much greater than it was. And that’s driven by people’s desire to recover files quickly from a random access device. People want to do this with ‘nearline’ data, stuff that might only be one or two weeks old. Plus this market is driven by the much lower costs of disk technology.”

Nevertheless, tape does maintain some desirable qualities that will continue to preserve the technology’s useful life. “The interesting thing,” adds Quantum’s Sparkes, “is that other forces in the market have been pushing our tape business into new places. For instance, an increasing amount of legislation and regulations are mandating that some businesses store data for 20 years or more. Tapes end up being the best medium to store things for a really long time because you can stick them on a shelf, they don’t take up space, don’t require heating or cooling, and they’re guaranteed to be readable for 30 years.”

Disk Driving Tape?

One of the other situations that Quantum’s Sparkes talks about is how the increased adoption of disk-based storage, a fairly recent trend, is actually fueling a newfound demand for tape.

“With new technologies like data reduction and data de-duplication, we’re seeing people storing two or three months of information on disk instead of the mere days that were possible when drives were much smaller. Now, you can imagine an organization configured around a central server, which is backed up to disk. Those external disk resources are almost inevitably right next to the server and therefore subject to the same threats of disaster and theft.”

Sparkes' point is that once you commit a massive amount of on-site storage to backup, whether it is through a networked 2U rackmount box loaded with nearline SATA hard drives or simply a direct-attached JBOD, you’re going to have a more difficult time getting saved data off-site.

Fortunately, difficult doesn’t mean impossible. There are a couple of ways to handle a mushrooming amount of offline data. The first, as we’ll see, is through clever use of data reduction technologies. Alternatively, you can archive to tape and move the redundant data somewhere safe. Ironically, the growth in disk businesses is thus paving the way or sales of tape in other places.

The short answer, according to Quantum’s team, is that tape is not dead. Although demand for tape is down overall, the general shift to disk-based storage technologies and a need to archive medical, legal, and educational records is feeding demand for tape in some of the verticals you probably address today.

Figuring Out Formats

If you’re easily frustrated by format wars, such as the back and forth between the Blu-ray and HD DVD camps, there’s a good chance you shied away from the many formats of tape backup. LTO, backed by Quantum, HP, and IBM; DLT, developed by Digital Equipment; and AIT, controlled by Sony, are all still popular today. Although Quantum owns the rights to DLT technology, it’s actually the fourth generation LTO-4 drives that Quantum’s Mike Sparkes is most excited about.

“The drive itself incorporates encryption,” says Sparkes, “which has really helped growth. It has enabled us to eliminate some of the risk involved in shipping tapes around in trucks.”

If your personal information hasn’t been compromised at some point because a major corporation or government lost data (perhaps you received one of those “we’re sorry to report...” letters from a brokerage or credit card company sometime last year), then you’ve at least heard the stories on the news. “A company must divulge that it lost data on its customers publically,” says Quantum’s Sean Lamb. “That’s where encryption comes into play.”

When encrypted data on a tape cartridge is lost, the responsible party is not obligated to report the loss since the information is considered inaccessible to anyone who might pick it up. For a VAR selling tape technology, that’s a huge boon. Not only does it prevent the massive material loss of sensitive data, but it also saves the public embarrassment of a business having to disclose the loss as well as the potential increase in customer attrition from lack of confidence in the vendor.

How can you be so sure that a lost LTO-4 cartridge is secure, even in the wrong hands? It features 256-bit AES-GCM encryption at the drive level. AES is the block cipher standard adopted by the U.S. government. There is no way to compromise the cartridge’s encryption algorithm through brute force attack. If your customer loses a tape, the information is truly unrecoverable by anyone else. LTO-4 cartridges also sport a native data capacity of 800GB. Performance is significantly higher than what you might otherwise expect from tape. LTO-4 drives top out at 120 MB/s, which isn’t too far off the real-world throughput of a SATA hard drive.

You can still find DLT tape hardware for sale. Quantum’s newest DLT-S4 tape drives hook up via SCSI and are able to push up to 60 MB/s. Don’t nudge your customers down that road, though. Quantum isn’t pushing DLT any more, and the benefits of LTO-4 make the technology more attractive when tape is preferable to disk-based storage. AIT is similarly faltering, despite the fact that the standard enjoys backward and forward compatibility between many of its generations. The latest iteration, AIT-5, enables 400GB of storage per cartridge and a comparatively pokey 24 MB/s of throughput.

Tape and Disk Together

You’re more likely to sell a combination of tape and disk backup than a pure tape play. The reseller able to turn customers on to the economic value of disk while still positioning the logistic advantage of archiving with tape is perhaps in the best position of all. Quantum’s PX502 tape library is designed to coexist in that exact sort of environment.

The 4U box has room for two 18-slot LTO magazines, which, when loaded up with LTO-3 cartridges, holds about 15.2TB of data. LTO-3 is also going to give you the best native performance at right around 580 GB/hr. You can configure the tape library in a number of ways, but in order to get the enclosure working with your disk-based storage solutions, you’ll either want to use the Fibre Channel FC1202 or the TC2201 Gigabit Ethernet host interface.

Quantum’s Scalar 50 is another tape library platform that offers a lot of value to businesses that rely on outside assistance to set up their IT infrastructures. In fact, Quantum even lays out guidelines to help resellers quote the Scalar 50, starting with a budget of around $10,000. Configuration is a piece of cake. You take the base system, set it up with the tape modules of your choosing (depending on format), select the right connectivity options, and bundle support services. Tied into an iSCSI SAN, the tape library can serve as a valuable tool for moving data to a secondary, secured site for long-term archiving.

Effective Data Reduction

Sparkes mentioned data reduction as an alternative to tape backup in the context of facilitiating backups via broadband to a remote server. Data reduction and de-duplication is actually a clever approach to minimizing the amount of information that is redundantly transferred from source to target.

“If you imagine a string of data that’s coming in, saved to disk, we have a software product that looks at that data, chops it up into smaller blocks of data, looks at each block, and creates a tiny signature that uniquely identifies that block,” says Quantum’s Sparkes. “Then the software stores that block onto disk, and it stores the signature into an index file. As more data comes in and the software examines each block, in addition to creating the unique signatures, it’ll also compare the signature with those stored in its index. If it sees a duplicate signature, it knows it has already stored that block for some other file. Take an employee’s name, for example. The name might constitute one block, resident in 20 separate files that we’re backing up. We store the signature in the index and the name as a block. In any future occurrence of that same name, we just refer to the first block.”

Obviously, the inner workings of the software aren’t quite that simple, but if you’re looking at databases across multiple servers, you’ll notice a lot of redundancy at the block level. Quantum claims data de-duplication typically cuts back capacity usage by a factor of about 20.

At the SMB level, Quantum sells complete appliances loaded up with its software. The entry-level DXi3500 model goes for close to $24,000, so it’s a serious piece of equipment. However, the 2U box is a complete solution able to turn 6TB of raw capacity into 210TB of retention capacity at 50:1 ratios, which you’d achieve through full daily backups.

However, with the DXi3500 on-site, keep in mind that you’re still facing the challenge of protecting information from a disaster. The ideal situation would be one unit on-site and another off-site. Because the de-duplication process results in so little new information being saved between day-to-day backups, it’s actually feasible to keep a pair of DXi3500s synchronized over a broadband connection.

You can get a small taste of the DXi3500’s capabilities in a more mainstream format by picking up Quantum’s GoVault, a true SMB product that combines the value of disk with the utility of a cartridge system. The GoVault is similar to Iomega’s REV from a hardware perspective. You can use everything from 40GB to 160GB cartridges that pull the cost per gigabyte of storage down below 10 cents. Performance hovers between 26 MB/s and 34 MB/s, which is much better than what you’d see from an entry-level tape solution. The real clincher is bundled data de-duplication software that can stretch those precious few gigabytes out at up to 20:1 ratios. In addition to plenty of capacity and a reasonable price tag, the GoVault is also portable enough to be used anywhere, on-site or off.

Tape Lives On

The good news for resellers protecting customers from data loss is that both disk and tape technologies are still viable today. Tape may be taking a back seat to the growing popularity and affordability of magnetic disk, but the two can be complementary in many situations, depending on how long the customer needs to store information.

Tape has definitely moved out of its role as a primary storage target and into the role of deep backup and archiving. Know when tape can add value. Simultaneously, know when a 2U networked storage box loaded with large, nearline SAS or SATA disks is going to do a better job of keeping sensitive data safe. Tape isn’t dead, but it is playing second fiddle and sidekick to a host of flexible, channel-friendly, disk-based solutions. Cover your bases with both storage formats.