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
- 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
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
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 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.
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.
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.
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.
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 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.
The archive function moves the files to the destination device for offline storage
rather than copying them.
Duplicate makes an exact image of a volume fully overwriting the existing information
on the destination device.
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
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.
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
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.
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.
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
- Powerful and flexible
scheduling and scripting
- Supports a wide variety
of backup devices
- Excellent User's Manual
- High Cost
- Unable to perform a bare
metal restoration using the client from a bootable CD
- Extended abilities can
4 out of 5 Mice