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Backup to the Future Q. What is “Backup-to-Disk” and why has this become important? A. Backup-to-Disk moves data to disk rather than tape to improve operational backup and restore. There are two benefits driving interest in disk-based backup. The first is that disk backup improves the speed and accuracy of data restores dramatically. Restores from tape are just not fast enough to meet service levels for many of today’s critical business applications. Not only can restores be faster and more reliable, taking just minutes rather than days, but backups can also meet more aggressive backup windows. These capabilities yield true business value. The second key driver is financial; the availability of ATA drives, with their high capacity and lower cost than Fibre Channel (FC) drives, has made disk backup more feasible by closing the gap between disk and tape costs. Q. Is this interest primarily with large organizations or small? A. The interest is widespread. Industry surveys, from the Taneja Group and Storage magazine, for example, indicate significant market interest and success in implementing disk-based backup. A significant proportion of ATA drive sales are being purchased for disk backup. Multiple vendors, both large and small are offering a variety of these solutions at various price points. With some products, the server host knows it is backing up to a disk array over a SAN or a LAN; for others, such as tape emulation disk library or a virtual tape library, the host still thinks its backing up to tape but, in actuality, its to disk. Q. What benefits are users realizing from Backup-to-Disk? A. Companies are seeing significant improvements in their backup and restore operations by implementing disk backup solutions. For example, one company’s restore times went from 24 hours when tape based to 2-4 minutes with disk. Other companies are seeing faster, more reliable backups as well as reducing costs associated with their tape operations. Another company installed a disk array and a disk library. They increased backup performance 60%, increased restore performance by 90% and reduced administrative costs by 25% as a result. Similar benefits have been realized by users deploying LAN implementations. Q. What about their existing tape infrastructures? A. Backup-to-Disk is not a 100% tape replacement initiative. Users and vendors realize tape has a role to play in their backup and restore operations, primarily for offsite archival storage, for duplicate backup copies and for those applications which have much less demanding service levels. This is why many suppliers of Backup-to-Disk solutions also offer tape products as well. Implementing a Backup-to-Disk solution will usually reduce the amount of tape in a customer’s operation. The user sees a reduction in their future tape acquisition budget as they can use the spare tapes to meet future tape needs. Q. Tape costs can be a significant percentage of a Backup and Restore budget. Is this how people justify a Backup-to-Disk implementation? A. Users justify their Backup-to-Disk deployment based on a reduction in tape expenditures as well as tape library and drive purchases as they may need fewer drives or smaller libraries. There are also people, vaulting and floor space savings because there is less tape to manage. Backup-to-Disk is selected for those applications that need faster, more reliable restores and/or backups. There is value associated with this benefit, such as higher application availability, reduced backup windows and improved access to data. Q. How does disk backup affect an organization’s existing backup software and processes? A. The major backup software vendors’ software supports both disk and tape backup; customers can continue to utilize their existing backup processes. In some cases, users may need to upgrade their software to do disk backups. What users like about Backup-to-Disk is the ability to leverage their existing infrastructure. This capability has high value to a prospective user. Q. How does a company assess implementation of a Backup-to-Disk solution? A. The customer needs to do an assessment of their current backup situation. There are a number of vendors who can provide professional services to help with this activity. The first thing to do is to look at all your applications and other data backed up. Reduce the amount to be backed up by eliminating inactive or stale data. The next step is to look at all your applications and see what service levels they require. Some may require the use of mirrors and replicas because of a high availability need. Other applications may be critical to the business but have lower service level needs. These applications (e.g. emails) are a good candidate for a Backup-to-Disk deployment, particularly if restoring from tape is consistently not meeting SLAs. A third category is those applications where service levels are not very stringent; these applications could still use tape for backup and restore. In summary, the company is implementing a tiered backup/restore strategy based on the importance of the value or criticality of the data to the business. Moving to a Backup-to Disk deployment varies by company, some start by choosing selected data and applications to try out the concept and add more applications later while others make a larger commitment from the start. Q. How do you see Backup-to-Disk evolving in the future? A. I see the distinction between backup/restore and replication products blurring. Products like continuous data protection, which has elements of both backup and replication, are starting to appear. However, there will continue to be a hierarchy of discrete products such as Backup-to-Disk at various price points to meet the range of customers’ service level requirements and environments. I expect disk-based backup offerings to be around for a long time. The product is moving out of early adapter mode and going mainstream. *** Allen Ruster is EMC’s Manager for Backup-to-Disk Solutions. Allen has over 10 years experience in the storage industry. He can be contacted at ruster_allen@emc.com or 508. 435.1000. Whitepapers on Backup-to-Disk are available at http://www.emc.com/solutions/continuity/b2d/
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