Dispelling common backup misconceptions

Posted on December 01, 2003

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By Heidi Biggar

When it comes to protecting data, users have an increasing number of options, which can make choosing the right product—or combination of products—a gargantuan undertaking for large data centers, small businesses, and those in-between.

The challenge is not only figuring out what data needs to be backed up, how many copies of data should be made, and on what device the copies should be stored, but also making sure that all backups are successful and that the data is readily accessible.

While no one product today can single-handedly address all aspects of data protection, there are a multitude of options beyond straight tape for backup, many of which work with existing tape infra-

structures. Many of the options can be plugged into local networks for quick, easy, and often low-cost data protection for remote sites or small and medium-sized businesses (SMBs), an often-overlooked segment of the market.

"The real trick these days, in our over-paranoid world, is figuring out what the true business continuity requirements are for each data type within the corporation and then aligning those requirements with the right data-protection scheme," says Steve Kenniston, a technology analyst at the Enterprise Storage Group (ESG).

The first step is to examine how your backup system works, explains Jacob Farmer, CTO at Cambridge Computer. Once you know how your data moves and what the bottlenecks are, if any, you can begin to apply technologies like disk-to-disk (D2D), virtual tape, continuous replication, etc.

However, Farmer offers a note of caution: "The problem with most backup systems is not that they're slow but rather that the bottlenecks are elsewhere [i.e., with the applications, clients, or backup server], and merely changing the storage medium will not make the problem go away."

"Vendors often try to sell technology that IT doesn't really need," says Kenniston. "Technologies such as replication, continuous backup, and even some snapshot implementations are not necessary in IT shops with less-stringent recovery time objectives. [In these cases, they can actually] chew up disk space and create more data management processes, which costs more money."

Along these same lines, installing disk-based backup may not fix an ailing backup environment, nor is moving your backup process off a LAN to a storage area network (SAN) necessarily the right thing to do.

"Every application and set of circumstances is different," says Dave Kenyon, director of enterprise product marketing at Quantum. "The important thing is to determine the user's specific objectives."

However, user objectives vary widely. For some users, the goal may be simply to get a basic tape infrastructure in place, while other users may require a D2D or disk-to-disk-to-tape (D2D2T) configuration. Still others may be looking to improve the speed of their backups, to consolidate their backup environment, or add a disaster-recovery component to their infrastructure.

Vendors are responding to end-user requirements in a variety of ways. For example, Breece Hill this month began shipping an integrated D2D2T appliance designed primarily for the SMB market. The appliance combines network-attached storage (1TB of Serial ATA disk), tape (a 1x10 autoloader with up to 2TB), and pre-loaded management software in a 4U rack-mount device. Breece Hill plans to integrate the appliance into an automation platform in the future.

"What I like about the Breece Hill product is that it's an integrated disk-tape-software solution that can back up any vendor's filer," says Dianne McAdam, senior analyst and partner with the Data Mobility Group consulting firm. "It not only backs up files to disk, but also automatically moves the files off disk to tape according to user-defined policies."

Unlike tape emulation ("virtual tape") or some other disk-based backup appliances, Breece Hill doesn't bill its product as a backup accelerator but as a remedy for network/server bottlenecks. Users can spend a lot of money on a backup accelerator and still not see any real benefits due to the limitations of their networks, according to Frank Saab, vice president of marketing at Breece Hill.

Unitrends, a provider of data-protection products and services, also cautions users about the virtual-tape approach. To take full advantage of the benefits of disk-based backup, users need to totally revamp what they're doing and how they're doing it, says Steve Schwartz, Unitrends' founder and CTO.

According to Schwartz, disk-to-disk backup should be integrated with tape but not to the point where the disk-based backup appliance is simply emulating a tape library. "We think virtual tape products are going to be just 'minor blips on the horizon,' " he says.

Cambridge Computer's Farmer says that virtual tape should be considered when users require the benefits of both disk staging and SAN connectivity and have the money to spend on such implementations.

Data Mobility Group's McAdam says that while some virtual tape products from vendors such as StorageTek and IBM have no place in some markets (e.g., SMBs) due to their high cost, other products such as Quantum's DX30 can help make backup/restore run faster and can help smaller companies consolidate tape operations and defer additional tape purchases.

"Virtual tape makes sense for SMBs because it can save money and solve the backup window problem," says McAdam.

Unlike tape emulation products and some other D2D appliances, Unitrends' Data Protection Units (DPUs), which provide disk-to-disk backup and bare-metal restore, do not work with leading backup applications; they can be used alongside, but not with, existing applications. The DPU runs proprietary backup/restore management software, with agents installed on all participating clients in the network.

Schwartz says that about 20% of Unitrends' customers use the DPUs solely for their bare-metal restore features; the rest make use of both their bare-metal and D2D (as well as traditional tape) features. The units can be plugged directly into a LAN or SAN.

Another option for SMB users is IntraDyn's RocketVault appliances, which provide local backup (using proprietary backup software and Serial ATA disks), local archiving, remote archiving, and off-site data protection (block-level synchronization) in Windows, Linux, and Mac OS environments.

Meanwhile, Quantum—an early entrant in the disk-based backup market with its DX30 virtual tape appliance—moved upstream recently with the announcement of the DX100. The DX100 provides 8TB to 64TB of disk capacity (compared to 3TB to 12TB for the DX30); has high-availability features, including RAID-5 support; and can push data at rates up to 2TB per hour.

Also targeting this market is ADIC, which in September announced the availability of its Pathlight VX integrated disk-to-tape backup system, which provides 8TB to 40TB of Serial ATA capacity and has RAID-5 support, 2Gbps Fibre Channel connectivity, and a 1TB-per-hour throughput rate.

Like most virtual tape products, the ADIC system works with existing backup software, which means no changes in software or processes are required. The VX also provides an integrated path from disk to attached tape (currently only ADIC Scalar libraries configured with LTO drives) for transparent movement between the two media types.

(For more information about disk-based backup, see "Evaluating options for disk-to-disk backup" InfoStor, October 2003, p. 34.)


Backup-and-recovery market

The Enterprise Storage Group expects the backup market to grow at a 16% CAGR over the next three years, accounting for some $3.7 billion in revenue in 2006 (see figure). Backup is the largest segment in the overall storage management software market.

ESG breaks the backup-and-recovery market into four segments: purpose-built software, systems and utilities; appliance-based software and systems; distributed software and managed services; and enterprise software.

While the enterprise segment (represented by traditional backup/recovery software) has been the historical workhorse, the newer market segments—in particular, purpose-built and appliance-based backup and recovery—are gaining end-user attention.

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Examples of vendors in these two market segments include Avamar, Storactive, DataDomain, Revivio, and FilesX (purpose-built software, systems, and utilities) and ADIC, Breece Hill, IntraDyn, Overland Data, Quantum, Sepaton, Nexsan, and Network Appliance (appliance-based software and systems).


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