Overview
Retrospect is an archival based backup utility that supports Macintosh OS X, Windows, and Linux. The Desktop version includes servers that run on Mac OS X and Windows platforms. Clients for each of these platforms are available to support backups over a local area network. Retrospect supports backups to a variety of media, such as Firewire drives, tapes, CDs and DVDs. Several backup modes are supported including full system, incremental, and drive imaging. The restore modes that are supported are full disk restore and individual folder and file restore.

Retrospect Server Requirements

• Macintosh G3 or better
• Mac OS X version 10.1.5 or later
• For Retrospect Desktop Client: A minimum of 128 MB RAM (256 MB recommended)
• For Retrospect Workgroup and Server: A minimum of 256 MB RAM (512 MB recommended)
• Hard disk drive with a minimum of 200 MB free space

Supported Devices
Retrospect will support any device that is visible on the Mac OS Desktop including a wide variety of optical devices, removable media devices and tape drives.

See the following location for more details on the supported devices: http://www.dantz.com/index.php3?SCREEN=compatibility_list

Evaluation Configuration
The evaluation configuration consisted of a 17" G4 iMac with 768 Mbytes of memory, an internal 80 Gbyte hard drive, a 200 Gbyte drive connected using Firewire 1394a and running Mac OS x 10.3. The Windows client is an eMachines 1794 with 640 Mbyte of memory and an internal 40 Gbyte hard drive rnning Windows XP Home. The Macintosh client is Rev. A iMac with 168 Mbytes of memory and an internal 40 Gbyte hard drive running Mac OS X 10.3.

Installation
Installation is as easy as double clicking the installer icon and accepting the license agreement. The license key will be requested on the first invocation of the tool. The license key will contain the activation for the clients if they are provided by the license.

In Use
Retrospect uses an archival approach for its backup process as opposed to the snapshot approach of the drive cloning methods, which ensures that a backup copy is not overwritten until you request it. Therefore, a history of a file is maintained over time, which allows the user to access to earlier versions of their information. Retrospect is able accomplish approach without using an excessive amount of space on the backup media through their use of incremental backup. The incremental backup approach only saves files that have been changed since the last backup.

Retrospect also offers the ability to select files or folders based on their characteristics. Selection of items is done in several ways. One approach is accomplished by identifying points in the volume hierarchy that are eligible for inclusion in the backup process. All files and folders at this level and below will be included in the candidate list of backup items.
Within the constraints defined by the volume list, additional filtering can be performed based on the characteristics of an item. These characteristics include the file's name and type or folder that they are contained in. An item may be included or excluded in the backup depending upon the criterion set. Boolean relationships can defined to express more complex selection criteria. Retrospect also supports the definition of "selectors", which are predefined criteria that can be included in the selection criteria for the backup. One selector allows the user to include all files except cache files. Another is used by the software compression option when it is turned on to disable it for any files that are already compressed.

In most cases, the file selection feature was as easy to use as the complexity of the Boolean expressions defined. In one instance, I had excluded all files from my backup, but the error was easily detected using the Retrospect's test scan feature, which generates a file list from the selection criteria provided. Additionally, the selector feature helped moderate the usage of more complex Boolean expressions and enabled reuse of these expressions.

Device Access
Retrospect uses the concept a Backup Set to define the location that a backup will be written. Retrospect then uses the device type selected to determine how to structure the files where the backup data are stored and how the backup will be conducted. In the file backup mode, the backup process will create a single file on the destination media and store all of the backup data in it. For removable media, Retrospect will fill one media item and then prompt the user performing the backup for a new media item. In this mode, it will create a file on each physical item and a directory file on the user's device of choice. If the directory file is lost, it can easily be recreated using the files containing the backup data. For Internet backups, the user will be prompted for FTP site log in information.

Restoration Methods

Full Disk
A full disk restore allows the user to restore a volume to a previous condition. In many cases, the user will be booting from the provided Retrospect CD and restoring data from a backup to produce a restored image of the drive. If a boot CD is not available, the drive will need to be restored from the most recent Apple Mac OS CDs and then restored by using the replace corresponding files feature.

Folder/File with Snapshot
Retrospect Snapshot is a list of file versions in the backup file that defines the state of the volume at the time of a backup. This restoration mode allows the user to restore a volume to an earlier state if needed, giving you confidence that the files coherently represent the state of the volume at that point in time.

Folder File Selection
If the user needs to restore a single file or folder from the backup, then they would use this mode. The user is presented with a description of the volume hierarchy from which they select the item to restore. Retrospect then creates a folder labeled for the Backup used. The selected items are then deposited into the new folder in the same relative hierarchical position that they originated from.

Client Restores
For a full disk restoration, Retrospect requires that the base operating system be installed followed by the client. For Mac systems, the restoration started by placing it in a particular state. This was accomplished by initiating the "Shutdown" process. The Retrospect client interrupts the "Shutdown" at a point that allows the restoration to take place.

For a Windows systems, the process is different. A temporary second OS installation is required, storing it in a different folder. The system is rebooted using the second OS and the client is installed. The restoration to the primary OS then takes place and the system is then rebooted using the restored primary OS.

Unfortunately, many OEM Windows OS restore CDs use a disk image format, which prevents the temporary OS image from being installed. This limitation makes it impossible to fully restore the system from a backup. Ideally, system restoration using the client would be much easier and less time consuming if Dantz would provide a bootable CD for both platforms with a functioning client.

Backup Methods

Backup
Backup lets you save files to a backup location for future access. When a backup process is first run for a Backup set, Retrospect will perform a full backup. For subsequent backup runs referencing a Backup Set, an incremental backup is performed.

Figure 1 - EasyScript Backup sample

As shown in Figure 1, backups are defined by the data source, destination, selection criteria, specific backup options and the schedule. The data source is defined through the selected volumes. The destination defines the location and device to use to backup the data. The selection criteria determine which files from the selected volumes to backup. The backup options are used to select verification or data compression. The schedule determines the times to run the backup process.

Archive
The archive function moves the files to the destination device for offline storage rather than copying them.

Duplicate
Duplicate makes an exact image of a volume fully overwriting the existing information on the destination device.

Backup Server
The Backup Server is an automated process that runs on a scheduled basis. It monitors the backup status of the computer connected to the network at the time of its execution and performs backup based on the recently computer was backed up. The more out of date machines get priority. The advantage of this approach is that introduces some flexibility to the backup strategy. The disadvantage is that a particular backup will not be run to completion. Dantz also recommends that a dedicated machine be used as a server. I used this approach for a while and found that it did not meet my requirements for completion of the backup. Furthermore, it interfered too much with my day to day usage of the backup machine.

Modes of Operation

Immediate
The immediate mode provides the ability to execute a function on demand. These functions include defining and executing a backup or restore as well as duplicating a disk or executing an existing script. You would use this mode if you needed to restore a recently deleted file from a backup or archiving a folder to CD or DVD. If you decide to execute a defined immediate job again in the future, it can be saved as a script.

Automated Scheduling
Scheduling of a script can use one of three modes, a recurring schedule, interval or a particular date. Any backup or restoration mode can be scheduled. In my case, I wanted to retain a minimum of four weeks of backup data, so I created two Backup Sets to house the backup data. Then I created a script that performed an incremental backup to Backup set A every night for a week. Then, I created three additional instances of this job to run the three following weeks. Each of these jobs was set to run on an eight-week cycle. In order to recover the space in Backup Set A, I created a Recycle backup job to run Sunday on an eight week cycle starting the same night as the first incremental job (eliminating the incremental backup history). Since Retrospect's scheduling engine recognizes that the single recycle job overlaps with the one night of the incremental backup jobs, it simply performs the recycle backup. In order to fill the remaining four-week gap, I create a second set of five jobs, four incremental and one recycle, which were offset by four weeks.

Figure 2 - Scheduling a Backup

The net result is that Retrospect initializes Backup Set A every eight weeks and fills out the remainder of the four weeks with incremental backups. It then switches to Backup Set B and performs the same actions for the next four weeks followed by a switch back to A. Figure 2 shows the four week cycle for Backup set B. Retrospect's ability to perform an automated backup using a policy this complex demonstrates the power of the scheduling engine. Note, I am able to achieve this level of automation by using a hard drive on which to store my backups.

Apple Script SupportThe script feature also contains an Apple Script event handler that passes control to Apple Script during the backup process. This feature provides the capability to notify administrators of various events that may occur during the process.

Reporting
Retrospect provides documents that status backups in two ways. The first is a high level view of the backup status of each volume. The second is an operations log that provides a detailed record of errors and performance of the backup process. I found the operations log the most useful since it provided a list of any errors that occurred, and I was interested in the performance metrics.

Documentation
Dantz provides an extensive amount of documentation in the Retrospect package. They offer an extensive User's Manual that provides a great deal of background information. One of the best features of the documentation is their detailed description of the steps needed to restore your computer back to a functioning state. In it, they discuss trying to recover the drive as well as backing it up prior to starting the restoration process. This section would serve as an excellent reference to use in a time of high stress. They also provide tutorials that I did not find that useful. On the other hand, they did provide Apple Script examples that I did find useful. Detailed scripts that email backup results are provided for a number of email clients, such as Mail and Entourage. In general, I found the User's Manual the most useful item in the documentation, particularly the contextual and background information.

Summary
Retrospect is a powerful professional level tool to backup your Macintosh. It provides extensive programmability that support automation of the backup process. The only limitation in this area is one due to the limited capacity of the available media, which reduces the user's ability to automate the backup process. Retrospect allows the user to utilize a number of backup strategies, such as disk duplication or incremental backups. It provides a great of flexibility in the scheduling backups. Retrospect also supports a wide variety of backup devices. The restoration methods also provide the ability to restore a full disk, a coherent snapshot of a disk or a corrupted file. Their archival backup method allows you to retain a historical record of your data that can be used in the event of you need to turn back the clock. The client backup capability allows you to consolidate your backups into a single location. Its only flaw is the lack of a boot CD with a functioning client that can be used to fully restore Windows and Mac systems from a bare metal hard drive without having to first load the base operating system.

Retrospect's power and flexibility tends to cloud the interface, making it somewhat non-intuitive. I found that the interface was not always conducive to determining how to configure the system, but now that I have some experience with setting up Retrospect, it is much easier to configure the system. The User's Manual is strong and provides a great deal of supporting material. The tutorials did not meet my needs.

Overall, if you need a professional level backup system, Retrospect would make an excellent candidate. Certainly, if you would like to backup multiple systems, the two client licenses provided with the base version makes it more attractive. Unfortunately, the high cost for Retrospect makes it hard to justify for the average single home system.


Pros

• Powerful and flexible scheduling and scripting
• Supports a wide variety of backup devices
• Excellent User's Manual

Cons

• High Cost
• Unable to perform a bare metal restoration using the client from a bootable CD
• Extended abilities can be non-intuitive

Overall Rating

4 out of 5 Mice