Exclusive: Data Domain DD460 Restorer puts the squeeze on data

The average compression ratio for all data in my tests in a first backup was 8.7-to-1; on the second backup of the same data, after changes had been made to some files, the average was greater than 400-to-1 compression. The DD460 achieves these levels of compression without undue processing time: Backups from a Linux system to the DD460 ran at 65MBps, and a Windows system backed up at 45MBps.

Free IT resource Virtualization Insights from Top Experts - Learn how virtualization gets real! Sponsored by Dell Free IT resource TechNet: More ways to know it, share it, and keep it running. Sponsored by Microsoft Data Domain DD460 Restorer Data Domain, datadomain.com Excellent  8.8 criteria score weight Management 8 25% Performance 10 25% Ease-of-use 8 20% Setup 9 20% Value 9 10% Cost: $75,000 to protect about 5TB of physical storage for as long as six months Bottom Line: Designed as a disk-to-disk backup target, the DD460 boasts incredible compression ratios, as much as 455-to-1 in realistic usage, with no impact on existing backup strategies. This enables administrators to tighten backup windows and makes the restore process very simple. With the DD460, a relatively small amount of storage is required to back up large amounts of data: A 1TB DD460 can back up 50TB of storage. About our Reviews and Scoring Methodology

Well-built machine

The system is very well engineered physically, with clean airflow and a nicely designed set of rack-mount rails that should work on pretty much any manufacturer’s rack.

Setting up the system is very simple, with DHCP supported for the initial network configuration. The quick-start sheet even includes MAC (media access control) addresses to ease DHCP setup. You can then use either a serial terminal or an SSH3 secure session for initial setup. Administrative tasks can be performed via serial terminal or SSH3. Fortunately, most administrative tasks must to be done only once. There is a Web GUI, but it is primarily for reporting functions.

The DD460 uses a Linux kernel from which extraneous functions have been pruned for added speed and security and to which necessary drivers and other modifications have been added. The system shows two partitions: /var, a utility partition that holds boot images, configuration data, and so on; and /backup, the normally accessible partition that stores backup directories.

When you’ve configured the network information, the rest of the process consists of adding shares and authorized users for NFS (for Unix and Linux) and CIFS (for Windows). If you run Windows in workgroup mode, you must add Windows host names, but that’s all that must be done. Backups then proceed as if the DD460 were any other NAS device.

Given the extremely high compression ratios the DD460 achieves, especially with data largely similar to previously backed up data, administrators may want to or need to change their backup strategies. They may want to replace incremental backups with full ones -- if their backup window allows for full backups -- because full backups require less storage space.

Shops running the DD460 can’t pre-compress data with tools such as gzip before performing a backup, because the pre-compression process randomizes the data stream. However, removing the pre-compression step ultimately simplifies and speeds backup and restore processes: Files no longer must be zipped and unzipped, the data streams are more compressible, and there’s less of a load on the network because the DD460 compresses in real time.

The Data Domain DD460 is far more reliable, easier to use, and speedier than disk-to-disk systems, making the appliance worthy of consideration by any organization interested in backup and restore alternatives.