ExaGrid vs Tape Library
For many years, backing up to a tape library has been the dominant method for performing backups to protect your organization’s data. Many IT organizations, however, have grown dissatisfied with tape-based backups and are looking for alternatives that offer fast backups and restores, scalability with no forklift upgrades, fast disk-based offsite disaster recovery, and a low IT maintenance burden . Disk backup with data deduplication is one such alternative, and it’s now available at a price comparable to a new tape library.
Why the move from a tape library? The problems with tape are well known: slow backups and restores, backups fail, restores fail, labels fall off, tape is mislabeled, and tape can be lost, stolen, or damaged. Tape backups must be monitored. Equipment needs to be maintained and heads cleaned for backups to be run properly. And tapes must be loaded and changed, labeled correctly, and physically transported off-site (and then back on-site) for disaster recovery.
According to Gartner and Storage magazine, 34% of companies backup their data to tape and do not test their backups. And an amazing 77% of those companies who do test their tape backups found backup failures (Boston Computing Network Data Loss statistics). Furthermore, a 2009 Symantec Disaster Recovery survey found that 65% of companies do not have adequate backup protection for virtual server environments. Many of these virtualized environments still rely on tape.
Disk, on the other hand, is fast and reliable for both backup and restores. The table below compares tape vs disk for selected attributes:
|Backups are slow
Tape libraries have a physical number of drives and therefore have a fixed number of concurrent streams. Also, tape libraries roll forward and backward (“shoe shining effect”) wasting performance time.
|Disk is fast
Disk is faster than tape as it is random access versus sequential access. In addition, with disk, you can set up dozens of NAS shares for concurrent streams.
|Backups are unreliable
Tape libraries are mechanical devices subject to failure over time. In addition, tapes get worn, dirty and damaged by heat and humidity.
|Disk is reliable
Disk does not wear, get dirty or get damaged by heat and humidity as disk is in a hermetically sealed case and lives in a heat and humidity controlled data center.
|Restores are slow
Restores are slow from tape because the tape has to be streamed to the point where data is stored—and the tape with the data may not be in the drive, not in the tape library, or could even be offsite. Even worse is the situation where the backup failed, and you won’t know it failed until you go to restore.
|Restores are fast
Disk is fast since it is random read versus sequential read, and with disk the data that is online is also on the disk. The chance of the data being on disk is 99.9999% because it is disk in a hermetically sealed case in a climate-controlled data center.
|Tapes are lost or stolen
Tapes move around onsite and are transported to an offsite location. Tapes are easily stolen or lost, thereby creating security issues.
|Disk is Secure
Disk sits in the data center rack secured by network and physical security. For an offsite disk backup system, the second system is also in a secured data center. All data is replicated in an encrypted form by the VPN.
|Tape Labeling is Error-Prone
Tapes are mislabeled or labels fall off.
|Disk Labeling is Automatic
No manual labor is required. Thus, no issues arise with human error or labels falling off.
ExaGrid’s disk backup with deduplication not only overcomes the challenge of tape, but it offers the following benefits:
- Fast backups: typically 40-90% faster than tape, utilizing post-process deduplication which lands the data to disk and then deduplicates after the data is already protected
- Fast restores: by keeping a full copy of the data on disk in non-deduplicated form
- Scalability: GRID architecture allows seamless scalability from 3.5TB to 320TB raw capacity, allowing full backups from 1TB to 130TB with no forklift upgrades or degradation in backup performance as data grows
- Offsite DR: an optional second-site configuration allows for WAN-efficient replication of data to an offsite disaster recovery location
- Low IT management burden: Customers using a plug-and-play disk backup with deduplication system typically spend only a small amount of time each week managing backups. Many report saving 10-20 hours/week or more vs tape, thus freeing time for more important IT priorities
In summary, ExaGrid’s disk backup with data deduplication eliminates the problems and management burden of tape with a solution that offers the fastest backups and restores, the only scalable architecture, and the only solution priced comparable to the cost of a new tape library.