Disk-Based Backup Unit Scores

Data Domain Inc.s DD460 Restorer backup appliance provides IT managers with another compelling reason to retire their tape backup systems.

Click here to read the full review of the DD460 Restorer.

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Data Domain Inc.s DD460 Restorer backup appliance provides IT managers with another compelling reason to retire their tape backup systems.

Disk-based backup has made major strides in the past few years, and its ability to back up and restore data speedily makes it better than tape for day-to-day operations.

The DD460 Restorer, released this month and priced at $75,000, also works with—instead of replacing—traditional backup software. Rival solutions, such as Avamar Technologies Inc.s Axion E, come bundled with backup software. This provides a more complete solution but doesnt preserve previous investments.

/zimages/7/28571.gifClick hereto read a review of Avamars Axion E.

While Data Domains older DD200 Restorer units were 5U (8.75 inches) in size, they had only 1.2TB of raw storage. With its upgraded hardware platform, the DD460 Restorer has 3.8TB of storage capacity in a 3U (5.25-inch) chassis.

Data Domains Global Compression technology further expands the storage of the DD460 Restorer many times beyond its raw capacity.

Global Compression works on the premise that data stored in file and application servers is rarely unique. As data is backed up to the DD460 Restorer, Global Compression breaks it down into segments that are then cataloged. When recognized segments are received, the DD460 Restorer acknowledges receipt of the segments but doesnt write them to disk.

For example, during an e-mail server backup, when a presentation is forwarded to a group within a company, the DD460 Restorer backs up the presentation only once, instead of saving a copy for each person who received it. Further, if one of the recipients edits personal notes into the presentation, the DD460 Restorer will store only the new information and not a complete version of the file. (Avamars Axion E has a similar capability.)

Data Domain claims to be able to provide roughly 20X compression for data backups of standard office data, and eWEEK Labs tests showed this claim to be accurate. However, we do not recommend using the DD460 Restorer in environments where large amounts of unique data (such as research labs and graphics studios) are created every day. We also do not recommend using the DD460 Restorer to back up files that are already compressed.

Gigabit Ethernet hooks the DD460 Restorer to the backup network, and our tests show that the appliance can back up and restore data at up to 80MB per second (using database and e-mail files in the test loads). In addition, file restorations on the DD460 Restorer were faster than tape because we didnt have to load multiple tapes to restore older files.

The DD460 Restorer has new replication technology that allows backup units to replicate over a WAN link. During tests, we used the DD460 Restorers WAN throttling feature to limit the amount of bandwidth used.

The DD460 Restorer has no bulk-load capabilities, which means that IT managers will have to send their entire data set over the WAN during the first synchronization session. IT managers with large amounts of data to back up should perform the first synchronization on a LAN.

/zimages/7/28571.gifClick hereto read about how Electronics For Imaging is using the DD460 Restorer to speed backup and file restores, and reduce off-site storage runs.

With the older DD200 Restorer units, a metadata repository was set up for each file system. When there was too much metadata, the file system could not be used for backups.

With the DD460 Restorer systems, metadata is stored along with normal file system data. This eliminates the e-mail backup inefficiencies reported with the older Data Domain units.

Next page: Evaluation Shortlist: Related Products.

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Evaluation Shortlist

Avamar Technologies Axion E Complete backup solution that includes storage and backup software (www.avamar.com)

FalconStor Softwares Virtual Tape Library Solid solution for IT managers who want to leverage SANs for backup (www.falconstor.com)

Check out eWEEK.coms for the latest news, reviews and analysis on enterprise and small business storage hardware and software.

Senior Analyst Henry Baltazar can be reached at henry_baltazar@ziffdavis.com.