Product Reviews

Originally starting life as a backup product for the Mac, Retrospect was ported over to Windows two years ago and is offered in four varieties - Express and Desktop for single users, Workgroup for small networks with one server, and Server, which includes a 100-client licence and can secure multiple servers.

Version 5.5 sees several useful additions, including a bootable CD image creator for disaster recovery and improved data restoration tools. Support for Windows 2000 allows the System State components to be backed up, and Dantz also includes a free Exchange 2000 agent with the Workgroup and Server versions.

A crucial difference between Retrospect and conventional backup software is that it doesn't play around with archive bits during backup. Before each backup, it scans the source hard disk, creates a Snapshot and stores it in a unique catalogue file. It then compares the files in the Snapshot with the last backup set and, if the same file is already listed, it won't copy it again. Collectively called IncrementalPLUS, this feature has a number of advantages, particularly when multiple backup copies are required for storing on-site and off-site.

A standard incremental backup switches the archive bit off after copying a changed file so the job can't be run again. If a duplicate is required, the tape will have to copy to another, which is inadvisable as errors on the original will be transferred to the copy. Retrospect allows you to do this by creating more than one backup set for the same task.

Another disadvantage when using a GFS (grandfather, father, son) tape rotation system occurs when the weekly partial copies are recycled the following week - any files that were created and deleted before the full copy is taken at the end of week will be lost for good. This won't happen with Retrospect, as it permanently keeps copies of all files secured.

On review are the Express and Server versions. Express doesn't support tape devices and only allows data to be backed up to removable media. I tested Express on a Pentium II/266

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with Windows ME installed and, when backing up 627Mb of data to an Iomega MO SCSI drive, it returned an average transfer rate of 37.5Mbytes/min. A reasonable performance, but with the 1.3Gb MO disks costing £17 each you're looking at overall storage costs of 1.27p per megabyte - a 4Gb DAT DDS2 tape, for example, offers storage costs of only 0.04p per megabyte.

Backups can be run on demand or scheduled regularly using Retrospect's script generator, which comes with plenty of Wizard-based help. After selecting the source files you want copied, choose your backup device and leave Retrospect to get on with it. Your first backup will copy all the files on your hard disk, but afterwards only those that have been added or changed will be secured. Data restoration is a simple process, as the Retrospect catalogues allow you to choose from any backup session and return files to their original location or to a new folder.

A Disaster Recovery Wizard guides you through the process of creating a bootable CD-R image. Choose the backup set you want to use and Retrospect will create an image directly to CD-R or the local hard disk, where it can be used to burn a disc later.

The Server version requires all workstations to have the appropriate client software loaded and this can be installed either locally or from a shared directory on the backup server. Users can't submit backup or restore jobs to the server but are able to ask for a backup to be run as soon as possible, during the normal schedule or after a specific time. Users are also allowed to select a backup run-time priority to determine its impact on workstation performance. Server scans the network and displays a list of all systems running the client and they can be placed in various groups for easier management. It's possible to protect sensitive data from unauthorised access with SimpleCrypt or DES encryption, and backup sets can be password protected.

Server was tested on a dual 1GHz Pentium III Dell PowerEdge 2550 with 512Mb of RAM and running Windows 2000 Server. Although it doesn't support NetWare or Unix systems, the Server management console can be run on any Windows system. It offers extensive device support, which includes the latest LTO (Linear Tape Open) and Super DLT drives along with tape libraries and autoloaders.

However, performance testing showed that Retrospect isn't as fast as ARCserve 2000, with the former returning speeds of 804Mbytes/min for an IBM LTO Ultrium drive and 592Mbytes/min for a Quantum Super DLT drive - a drop of around ten per cent from ARCserve. Even so, Retrospect is a solid alternative to conventional backup software.