Metadata, Load Balancing and
Smart Sizing"> Another interesting facet of the VTL600s file system is that it embeds metadata into each of its disk streams. As a result, if a head unit dies, an IT manager can plug the disk shelves into a new VTL600 to quickly rebuild its metadata repository. The VTL600s metadata repository is used to locate specific backup jobs with the VTL.The load balancing intelligence built into the VTL600 automatically distributes the load from incoming backup streams to the four disk shelves. This is the first VTL system weve seen with this kind of load balancing capability. The VTL600 lacks data deduplication capabilities such as those found in Avamar Technologies and Data Domains VTL products. Deduplication technology eliminates redundant files and minimizes the amount of data stored when files are updated. Click here to read a review of Avamars Axion E, a one-stop disk-based backup system. However, the VTL600 does have a feature called Smart Sizing that will increase storage efficiency. Smart Sizing can be used to intelligently set up virtual tape sizes. When backups are written to tape, the type of tape drive used and the properties of the data being backed up determine the amount of compression that can be achieved. For example, while little or no compression may be possible when backing up a .zip file, compression ratios of 3-1 could be achieved when backing up a database or text files. This will help IT managers minimize management and acquisition costs for tapes. The VTL600 also can migrate tapes directly to a physical tape library by writing the virtual tape images stored on its disks to the tapes on an attached tape library. This not only reduces the migration load on media servers but also allows IT managers to maintain consistent bar codes between virtual and physical tapes. With other library solutions, such as Data Domains DD400 Enterprise Series, IT managers need to use the tape cloning functionality in their backup media servers to migrate data from virtual tapes to physical tapes for off-site storage or long-term archiving. Data Domains Virtual Tape Library option for enterprise storage significantly cuts down on bandwidth costs. Click here to read more. The VTL600 offers three different migration techniques for creating physical tapes: The Copy and Replace method turns a virtual tape into a physical one when data reaches a specific age and automatically deletes the original virtual tape; the Clone and Replace method immediately creates a physical tape when a virtual tape is completed and automatically deletes the virtual tape; and the Clone and Offsite method retains the virtual tape but creates a clone that can be sent off-site for disaster recovery purposes. Next Page: Evaluation shortlist.
The VTL600 hooks into a backup SAN (storage area network) using Fibre Channel ports on the head unit. After we created a virtual library using the VTL600s management tool, the Symantec Veritas NetBackup 6.0 media management server with which we were testing was able to quickly locate the new VTL and write backup jobs to it.