mrr@amanpt1.zone1.com (Mark Rinfret) (06/15/88)
I see MRBackup V2.2 is finally making its debut. I thought I was going to
have V2.3 ready before V2.2 got out :-). Please note that the document
distributed in the V2.2 release is actually for version 2.1 (my fault, not
the moderators'). Please accept my apologies and replace it with the copy
that follows.
Thanks,
Mark
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MRBackup Version 2.2
A Hard Disk Backup Utility
for the
Commodore Amiga
2 April 1988
Mark R. Rinfret
Introduction
This document describes a program, named MRBackup
(pronounced M R Backup, not Mister Backup :-), which will allow
you to backup the files on an Amiga hard disk drive to floppy
disk media. I wrote MRBackup primarily out of my own need. I also
saw it as a means for learning more about programming the Amiga.
Please take the time to read this document carefully. There are
some fine points ("Now THOSE are some fine points!") about the
program that you won't want to miss.
MRBackup is reasonably flexible, allowing you to back up
individual directories, directory trees or a whole disk. You can
backup from one directory hierarchy and restore to another.
Incremental backups can be performed based on file modification
dates. MRBackup also uses, at your discretion, the "archive bit"
feature added with release 1.2 of the WorkBench. Just for fun,
MRBackup also talks. Though this is may seem frivolous, the
speech capability provides a method for alerting you that a new
output disk is required for formatting.
MRBackup is not fast. When choosing a method for packing the
backup data, a fast-scan approach with specialized backup
directory structure was considered. However, there is an inherent
danger in committing multiple files to a specialized file system
which can only be accessed through a solitary piece of software.
I decided to maintain the AmigaDOS file system structure which
has a great deal of integrity and allows the backup media to be
accessed by standard software. When I do it again, I'll probably
go with the specialized approach - the current method is just too
darned slow.
The user should take a serious and organized approach to
his/her backup methods, however. I highly recommend that backup
listings be kept in a safe place (I use a 3-ring binder) and
backup floppies be stored safe from magnetic damage or other
hazards (like spilled coffee - argh!). A truly committed
individual will backup his entire disk once a month, once a week
and "areas of interest" once a day (default).
MRBackup attempts to economize on output media usage by
using Lempel-Ziv data compression/decompression (at the cost of
time). This is an option which can be enabled/disabled via menu
selection. The compression routine used was lifted from the Un*x
"compress" program but has been adapted to employ buffering and
native AmigaDOS I/O.
Operation
To use MRBackup, click on the program icon or type MRBackup
at the CLI prompt. A new window will open in which you will see a
STOP sign, some other gadgetry, and a couple of embedded
windows. If you click with the right mouse button and drag from
left to right across the menu bar, you'll see the various program
menus which control MRBackup's operation.
Pathname Specifications Window
The Pathname Specifications window is where you tell
MRBackup where data is coming from and going to. It is important
to note that the meanings of "Home Path" and "Backup Path" remain
the same for a backup or a restore operation. That is, the "Home
Path" always refers to the files' normal "home" and "Backup Path"
always refers to the location where the copies are kept.
The "Listing Path" refers to the destination of a detailed
listing of the contents of the backup floppies and may specify
the printer (PRT:, default) or a file on the hard disk. The
listing is an option which may be enabled/disabled via a Flags
menu selection.
The "Exclude Path", if specified, is the name of a file
which contains lines describing files which should not be backed
up. Any filename matching an entry in this list will be excluded
from the backup. The exclude file consists of file
specifications, one per line, or comments (a line with a number
sign - # - in column 1). Blank lines are ignored. Also, the
specifications are case-insensitive. That is, "SYSTEM" and
"system" are equivalent. Examples:
# Exclude all object files
*.o
# Exclude all files beginning with "System":
system*
# Exclude all ".info" files:
*.info
# Exclude the "include" directory and all subdirectories:
include
The "Preferences" pathname allows you to specify the name of
a file holding your current MRBackup preferences. You can
customize the operation of MRBackup through the use of an
initialization file. When you first run MRBackup, it looks for
the file named MRBackup.init, first in the current directory,
then in the S: directory. Each line in the file consists of an
option setting, of the form:
OPTION = VALUE
or a comment. Comment lines begin with a number sign (#). A
sample initialization file is included which illustrates the use
of all possible parameter settings.
The following example is from a working MRBackup initialization
file:
# The home path is the name of the hard disk.
home = DH0:
# The backup path is the external floppy disk.
backup = DF1:
# Send the listing to a file on the hard disk.
# The default is PRT:
list = S:MRBackup.list
# Give the name of the file containing exclusion specifications.
exclude = S:MRBackup.xcld
# Employ file compression / decompression.
compression = YES
# Disable the listing capability.
listing = NO
# Let MRBackup talk to me.
speech = YES
# Format each floppy targetted for output.
format = YES
# Do special processing for "big files".
bigfiles = YES
# Provide special handling of the "archive bit".
archivebits = YES
Backing Up a Disk
To back up your hard disk, or a section of it, first get an
indication of the size of the area with the Info command, "ls"
(if you have it), List, etc. If you multiply the total number of
bytes (blocks * 512) by 0.65, then divide by 800000, you should
get a very rough estimate (probably high) of the number of floppy
disks required to back up that area. The floppies selected for
backup need not be preformatted, as MRBackup will format them as
needed. You should be sure, however, that no valuable data exists
on them since it will be destroyed by the formatting process, if
formatting is enabled.
Once your floppies are ready and stacked neatly within reach
(get some labels and your favorite marker pen, too!), the fun
begins. First, modify the pathname specifications according to
your requirements. Normally, the "Home Path" would be the device
name of your hard disk or a directory on it (e.g. DH0:) while the
"Backup Path" would specify the device name of one of your
floppy drives (e.g. DF0:). While earlier versions of MRBackup
were pretty rigid in this regard, this version will allow you to
specify ANY disk device name in either specification. PLEASE BE
CAREFUL! Many users asked for this increased flexibility. Just
be aware that it carries with it an increased risk that you now
have more "opportunity" to burn yourself with improper pathname
specifications.
Finally, the listing path may be set to the printer device
(PRT:) or to the name of a file on a hard drive or any available
floppy drive not being used by the backup. The listing path will
be ignored if you disable the Generate Listing option in the
Flags menu.
Make sure that you have set the desired options in the Flags
menu, then select Backup from the Project menu. You will be
prompted with a date requester. The default date value that
appears is one day earlier than the current date. If that is
satisfactory, simply depress the RETURN key and the backup will
commence. If you desire to change the date, edit the date value
as necessary, using the standard Amiga conventions. Remember that
to clear the gadget you may press right-Amiga-x. A null date
value (all blanks) is allowed, should you want to backup all
files in the home path, regardless of their creation dates. The
minimum date value handled by this date requester is 03/01/84
(though AmigaDOS supports dates back to 01/01/78). The required
date and time format is MM/DD/YY HH:MM:SS (24 hour clock), the
time specification being optional. You will notice upward and
downward pointing "arrows" above each date component. Clicking on
the appropriate arrow will increment or decrement the respective
portion of the date. Though the values normally will wrap around,
not affecting adjacent date components, certain situations will
arise where incrementing a day value may cause the month to
increment (incrementing February 28 in a non-leap-year will yield
March 31).
Once the date has been entered, the rest is fairly
automatic. You will be prompted immediately for a floppy disk.
Insert it into the floppy drive that you specified in the backup
path and the disk requester will be satisfied. Should you want to
abort, simply hit the CANCEL gadget in the requester. Also, you
may abort the backup process at any time by hitting the STOP
gadget which appears in the top left area of the screen. This
gadget is checked prior to each block write operation, so be
patient if it does not respond immediately. Use the STOP gadget
with caution - it really lives up to its name!
As each floppy disk is filled, you should promptly label it.
If formatting is enabled, MRBackup automatically generates volume
names of the form:
Backup MM-DD-YY.<sequence number>
Also to be noted is the fact that the files on the backup media
retain the creation/modification date, comments (FileNotes) and
protection bits of their counterparts on the home device.
You will find that the Amiga's multitasking environment
shines when using this program. For those long-haul backups, get
everything started, then shove MRBackup's screen to the back and
go start something useful. MRBackup will carry on without your
watchful eye. When it needs a disk, the disk requester will pop
out in front of everything and MRBackup will ask (out loud, if
speech is enabled ) for another disk. Having something else to do
will make the time pass faster.
Restoring the Backups
No, this isn't always the bad part. Backup and restore can
also be useful when your hard disk is crowded and you have to
"juggle" data around. The restoration process is quite similar,
mechanically, to the backup process - it's just reversed. In
addition, the meanings of the pathname specifications are altered
somewhat. The "Home path" describes the destination for the
restored files and, as with the backup process, may specify the
hard drive only or a directory specification. The "Backup path"
describes the file or files to be restored and thus may be
defined down to the file level (1 file).
Note that on a restore operation, the file creation date of
the backup file is compared to its matching file (if it exists)
on the home device. If the file on the home device is newer, the
file will not be replaced. If this is desired, the file on the
home device must be deleted first. A later version of this
program will probably offer a "force" or "force with prompt"
option.
Menus
This section provides a brief description of MRBackup's
menus and their items.
Operations Menu
The Operations Menu provides access to MRBackup's major
processing functions. They are:
About
This item gives a quick description of MRBackup's
features and lists my address and phone numbers.
Backup
This command begins the backup process. You should
first be sure that all Pathname Specifications and Flags
menu settings are correct.
Resume Backup
This command allows you to backup your hard disk in
stages or recover from an interruption, such as a power
failure. Prior to "starting" each backup floppy, MRBackup
writes information about its current internal state to a
file named S:MRBackup.context. The first line of this file
is the disk sequence number (1..n). The second line is the
name of the first file to be written to the floppy. The
third line is the backup "delta date". Subsequent lines are
the names of files and directories in MRBackup's top-level
file list. As long as the file specified in line 2 can be
found, MRBackup should be able to resume your backup, even
if changes have occurred since the original backup was
interrupted. You may even edit the context file for special
situations where you wish to backup a disjoint set of
directories.
Restore
Restore allows you to recover files from backup
floppies previously created with the Backup or Resume Backup
commands. MRBackup will prompt you for floppy disks as they
are needed. Note that there is no prescribed order for
restoring floppy disks.
Load Preferences
This command reads your Pathname Specifications and
Flag menu settings from a file named S:MRBackup.init. You
would typically use this command to restore MRBackup's
settings to your startup settings.
Save Preferences
This command writes the current Pathname Specifications
and Flag menu settings to the file S:MRBackup.init. This
allows you to establish MRBackup's default initialization
parameters. MRBackup will attempt to make a copy of the
current preferences to a file of the same name, but with an
extension of ".bak". If the preferences name you have
specified does not currently exist, MRBackup will inform you
that it could not make a backup. Ignore the message in this
case.
Quit
Alas - all good things must come to an end. As much fun
as MRBackup is to use, you'll probably want to put it away
once in a while.
Flags Menu
The Flags menu allows you to set or clear certain
operating parameters (flags) which constrain MRBackup's
operation. A flag is considered "set" if there is a
checkmark to the left of its name in the Flags menu. Each
time the item is selected it will toggle to the opposite of
its current state.
Compress Files
This option, when set, allows files to be compressed
during backup and decompressed when restoring. File
compression can typically save from 35% to 60% of the
original file size. Though this is more costly in terms of
time, fewer floppies will be required to perform a backup.
Do Big Files
Big files are files whose size exceeds the formatted
capacity of a floppy diskette (1756 blocks). In order to
backup big files, MRBackup must split them across two or
more diskettes. In order to accomplish this, a special
information file, MRBackup.bigfile, is written to each
backup diskette containing a big file. MRBackup also
requires another flag, Format Destination, to be set in
order for big file backup to be attempted. If these
conditions are not met, MRBackup will simply skip over the
big file, reporting the event.
Generate Listing
This option causes MRBackup to list the contents of
each backup diskette (created by the Backup command) to the
file or device specified by the Listing Path in the Pathname
Specifications window.
Speak
Setting the Speak flag allows MRBackup to talk to you.
This is especially useful when doing backups. When a new
floppy disk is required, MRBackup will call you for help
(it's a pity the Amiga doesn't have a diskette jukebox
feature).
Format Destination
This flag is normally set and tells MRBackup to format
each floppy used for backup purposes. However, you may wish
to disable this feature for special backups which you prefer
to "refresh" by writing over previous versions of backed up
files.
Use Archive Bits
A new feature, added with release 1.2 of the WorkBench,
is an archive bit in each file's protection word. This bit
is cleared whenever a file is modified and can be set by
MRBackup when a file is backed up. When this option is
enabled, files for which the archive bit is set will not be
backed up. This gives you a very accurate method for backup
selection if you're careful with your backup diskette
library.
Windows Menu
The Windows menu allows you to reactivate windows which have
been closed. Currently, the only window supported in this manner
is the Pathname Specification window, which you may close once
all pathname specifications have been made.
Warranties and Support
There are no warranties, either expressed or implied, with
regard to the use of this program. You didn't pay for it (did
you?), so how's you gonna' get you money back (sic, sic, sic)?
Seriously, folk, I've tested this beastie pretty thoroughly (I
USE it!), but you know how things go. There may be a bugaboo or
two lurking about. Please exercise it a little before committing
your life (your precious data) to its care.
As for support, I will do my best to respond to bug reports
for as long as I have an Amiga in working condition. I will only
support the most recent version, so please know your version
number if you call. I am a fairly trusting sort, so if your need
is urgent and I have a spare floppy, I'll probably respond right
away and assume you'll return my floppy and a couple of stamps in
equally prompt fashion.
Several people have suggested that I should have made this a
shareware product, if not a commercial one. I don't really think
that shareware works, and it really was not my intention to make
money with this program. I can see in retrospect, however, that
there was a need for such a utility and that with a little more
work (OK, a lot of work!), I could probably have had a minor
financial success. However, by my standards, that would have
required a lot more effort and commitment than I had to give at
the time. Your calls and letters have been extremely gratifying
and all the incentive I've needed to continue to steal a couple
hours here and there to continue making improvements. (If anyone
wants to talk a deal for some reasonably priced custom software,
I'm all ears.)
Permissions
This program is contributed to the public domain, as a token
of gratitude for the many wonderful programs I have received
through the same channels. Feel free to enhance, destroy, sell,
distribute or otherwise benefit from the legal use of this
program. I would love to hear from those of you who find MRBackup
either useful or useless (with specific criticisms in the latter
case). If you make any enhancements (there's room for PLENTY),
please share them with me and the rest of the world. I can be
reached as:
mrr@amanpt1.ZONE1.COM
...rayssd!galaxia!amanpt1!mrr
or
Mark R. Rinfret
348 Indian Avenue
Portsmouth, RI 02871
401-846-7639 (home)
401-849-8900 (work)
Changes
This section lists changes, in reverse chronological order,
as they have appeared in subsequent releases of MRBackup. I have
attempted to be thorough, but may have missed a few key items.
Version 2.2
MRBackup now searches the current directory for
MRBackup.init upon startup. This allows you to have custom
backup preferences for separate projects which are automatically
found if you start MRBackup using the CLI interface from the
directory containing the file MRBackup.init.
Prior to this release, the specification of a new listing
path caused the listing to be immediately rewritten. This was
not a GOOD THING since your old listing file could be destroyed
before you got a chance to select a new name. Now, MRBackup uses
append access when testing the listing pathname for
accessibility. It still rewrites the file once the backup has
started, however.
I've added a few more messages to greet you when MRBackup is
first started.
Most people who have had trouble with MRBackup did not
understand the purpose of the file change delta date ("since
date") requested when a backup was started. They typically would
let it default, then not understand why more files weren't backed
up. I have changed the default to include all files. This is
probably more useful, especially with the new archive bits
feature.
Version 2.1
Added the "archive bits" capability.
Fixed an error in the file exclusion list processing
algorithm. While this problem seems to have drawn little
attention, the previous algorithm did not properly handle file
specifications involving nested directory components.
File comments and protection bits now are saved/restored
along with the file date.
A new command, Resume Backup, plus a new method for saving
"context" information, has been implemented.
Version 2.0
New User Interface
MRBackup has undergone a major facelift. It now has its own
screen and color palette and newly designed menus and gadgetry.
All of this is due to my use of PowerWindows 2.0 from
Inovatronics, a very worthwhile tool for Intuition programming.
You will notice some new gadgetry on the screen. I've added
a "fuel gauge" which indicates the "fullness" of the output
floppy. There's a new error count gadget which tracks total
errors encountered and a "Current Backup Volume Name" gadget
which keeps you informed as to which disk you're currently
archiving to or restoring from.
The Pathname Specifications window has a close box which
will make the window go away. A new menu, Windows, has an item
Pathnames which will reopen the window for you.
A new command, Save Preferences, allows you to save your
current pathname specs and flags to the preferences file
(S:MRBackup.init). The Flags menu has been totally redone. This
menu previously consisted of item pairs (<feature>/No <feature> -
pretty dumb, I must admit - I think I was intrigued by mutual
exclusion at the time). The new Flags menu just consists of
check-marked items. If an item is checked, the feature is
enabled.
Improved Error Handling
This is usually the hardest task in any programming chore
and usually gets the least attention. Previous versions of
MRBackup were no exception. Version 2.0, however, has come a long
way in this direction, especially in the area of recoverability.
A new requester has been introduced which lists your recovery (or
abort) options when certain errors have been detected. Most
significantly, new context-saving code has been added which will
allow you to restart a backup disk from its beginning, should a
non-recoverable output error occur. Currently, this context
information is saved in memory. I would like to save it to a file
on the system disk. This, coupled with
a new command (Resume Backup), would allow recovery even from a
power failure.
Increased Flexibility
Previous versions of MRBackup were fairly rigid with regard
to home and backup path specifications. Version 2.0 allows ANY
disk device to be referenced in either location. On systems with
dual floppy disks, you can even backup from floppy to floppy!
MRBackup now allows you to suppress formatting of the backup
disk. This allows you to "freshen" a previously created backup
set. Though this option should be used with care, it does speed
things up and enhances MRBackup's partial backup capability.
Big File Handling
This is truly a last-minute item! I personally don't have a
file big enough to require this, so I didn't address the problem.
However, enough users have requested this that I took a stab at
it. "Big" files, according to MRBackup, are files which are
larger than the formatted capacity of the output media. Iff (sic)
you enable the "Do Big Files" and "Format Destination" Flag
menu items, MRBackup will split
big files across multiple floppy disks. If these options are not
enabled, MRBackup will just complain that the file is too big to
back up and go on.
Some of you will probably think that the method used to do
this is somewhat kludgy, but it's consistent with my approach to
total AmigaDOS compatibility. When backing up a big file, a
special information file, MRBackup.bigfile, is written to the
output disk. The information file contains stuff like the file
name, the "chunk number" (which piece of the file is this?), the
chunk size, and a flag which indicates whether this is the last
chunk. This information is used by the restore operation to
insure that the file chunks get reassembled in the correct order.
In order to test this, I had to write a program to create a
big file (slightly larger than 1 floppy disk), archive it and
restore it, then compare the two files. To do all this, I had to
first clean house on my 20 MB hard drive! The big file backup
appears to work OK. I think it could use some more testing,
however, and would encourage you to test drive it before you
commit to it.
--
< Mark R. Rinfret, mrr@amanpt1.ZONE1.COM | ...rayssd!galaxia!amanpt1!mrr >
< AMA / HyperView Systems Home: 401-846-7639 >
< 28 Jacome Way Work: 401-849-9930 x301 >
< Middletown, RI 02840 "If I just had a little more time...">