dsmall@mitre.org (Duane Small) (02/21/91)
I recently requested user comments on software for backing up and
restoring a hard disk to/from floppies. I mentioned Disk Fit, Fastback
II, and Redux as candidates, and I invited comments from users of other
software as well.
Thanks to all of you who responded. I received responses from 6
users of Fastback II (including one of the people who developed it), 6
users of Disk Fit, and 4 users of Redux. (People reporting on two
packages are counted twice). I also received 4 recommendations for
Retrospect and 1 for NetStream.
Below is an overall impression, followed by a discussion with respect
to each of the criteria I mentioned in my original note. I've collected
and summarized, so some loss of information is inevitable, but I hope I've
managed to be true to the comments I've received
Overall Impression
Retrospect users were the most enthusiastic of my respondents. Of
course, I am unlikely to receive negative comments about software that I
had not identified as a possible candidate :-). One person did mention
that Retrospect is the most expensive backup software. Although
Retrospect will back up to floppies, the people who recommended it
apparently were using it for backup to tape. Retrospect will also back up
across a network.
The report on NetStream was also positive. It features automatic
backup on a user-specified schedule, or a network admininstrator can
schedule unattended backups at predetermined times, apparently to the
central network server. It can back up to "anything that the user can
mount on the desktop." It is also quite cheap (about $57).
Fastback II is apparently the fastest of the three I mentioned in my
original note, and the only one that significantly compresses data. It is
also the only one that got really negative comments: unreliable backups
(may have been disk problems rather than software problems); difficulties
with the backup set if the backup is cancelled in the middle and then
restarted; and either mild dislike or utter detestation of its interface
("sacrifices too much usability for speed and small archives"). Not
everyone was negative. One user (not the developer) said the package was
"very intuitive" as well as powerful and flexible.
Disk Fit and Redux were both well liked by all who reported on them.
Redux appears to be more powerful; but while it is reported to be easy to
use, it may be less suitable than Disk Fit for users who don't want to
know anything about computers.
Discussion Organized by Selection Criteria
My earlier note suggested four evaluation criteria for backup
software: support of selective backup, incremental backup capability,
support of selective recovery, and ease of use.
Selective Backup
Disk Fit
In Version 2.0, files can be selected for backup by the folders they
are in, and/or by modification date, creator, type, etc. There is also an
option not to back up files for which the size hasn't changed since the
last backup (for example, to avoid backing up Hypercard files that haven't
really changed). If you select a folder to be backed up, only files in
that folder are backed up--folders inside the folder must be identified
separately. (Versions before 2.0 offered much less flexibility.)
Redux
Files can be selected for backup by individual file, by the folders
they are in, and/or by modification date, creator, type, etc. If you
select a folder to be backed up, the default is that all folders inside
the selected folder are also backed up.
Fastback II
Fastback II permits selective backup, but none of the respondents
gave any details.
Retrospect
Selectivity was reported excellent, and one comment mentioned
situations in which only specific files are being backed up. No one gave
details. (If you offered me details and I didn't include them, there was
a mail failure--I requested additional information from two people who
offered it, but received only one response.)
NetStream
Files can be selected for backup by disk, folder, file, and file type.
Incremental Backup
Disk Fit
Old versions of files that have been changed and files that have been
deleted are removed from the backup set when one does an "incremental
backup." The result is a single backup set (rather than a base set and a
set of increments) that matches the current status of the disk.
Redux
One person mentioned that during incremental backup, Redux reclaims
unused space in the backup set. I infer that it may (like Disk Fit)
delete old versions of files, and it may keep a single backup set rather
than a base plus increments. However, I have no definite information on
those points. One person who used Disk Fit said he thought (from research
prior to purchase?) that Redux kept old versions of modified files.
Fastback II
Incremental backup is one of several options available. Another
option is a difference backup that creates a "difference" set from an
original base set, ignoring the intermediate backups, so that the base set
and *one* difference backup suffice to recreate the disk. At least under
some options, more than one version of a file is retained in the backup
set.
Retrospect
Incremental backup is the normal operation. I have no details on the
mechanism.
NetStream
Both incremental and archive backup are available. I have no details
on the mechanisms.
Selective Recovery
All allow selective recovery. Most (apparently all except Disk Fit)
use facilities within the program for recovery. Disk Fit stores backed-up
files in Finder format. To recover, you look in a backup report to find
which floppy the file you want is on, then insert that floppy and use the
Finder to copy the file back to where you want it.
Ease of Use
Usability may vary by function, and users tended to give me general
impressions about *overall* ease of use . . . .
Disk Fit
Aside from one minor complaint about a confusing dialog box, reports
were uniformly positive. One respondent mentioned that secretaries had
been using the package for a considerable time with no problems. The
multi-stage selective recovery process may seem awkward to some, but the
ability to use the Finder was regarded as a plus.
Redux
Everyone reported Redux to be easy to use, but one person who made a
direct comparison said that it wasn't as easy as Disk Fit. Redux has more
options, including a scripting language for automating processes that will
be repeated.
Fastback II
Comments ranged from "very intuitive" through "somewhat kludgy" to "I
hate the package."
Retrospect
Again, since I hadn't identified the package as a candidate, I only
heard from those writing to recommend it, and they all loved it. I'll
quote the one detailed comment: "Retrospect is very easy to use -- about
as easy as I could imagine this kind of a program to be. It divides the
process up into 4 major steps, and normally you just need to pick the
default actions at each step. If you customize any of the steps, it
remembers those custom changes and does it that way the next time you run
Retrospect. There are some scripting capabilities, but I've never needed
to use them."
NetStream
There is more than one level of interface. There are scripting
capabilities for those who want the flexibility, and there are
double-click visual methods for those who want to keep it simple.