Amiga Collections: Taifun/Taifun 054 (1988-05-15)(Ossowski, Stefan)(DE)(PD).zip/Taifun 054 (1988-05-15)(Ossowski, Stefan)(DE)(PD).adf/MRBackup/MRBackup2.0/MRBackup.TXT

Text File | 1988-04-09 | 16KB | 529 lines

                      MRBackup Version 2.0

                   A Hard Disk Backup Utility
                             for the
                         Commodore Amiga


                         2 January 1988

                     Author: Mark R. Rinfret
















































Introduction

     This  document   describes   a   program,   named   MRBackup
(pronounced M R Backup, not  Mister  Backup :-), which will allow
you to backup 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.  If you are
already familiar with this  program,  you may want to jump to the
"Changes" section at the end of  this  document.  Otherwise, read
on.

     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.  Just for fun, MRBackup also talks.  Though this is mostly
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
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 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 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.


     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 (default) or a file on the hard disk.  The listing is
an option which may be enabled/disabled via 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
# Exlude the "include" directory and all subdirectories:
include

     You can customize the operation of  MRBackup through the use
of   an   initialization   file.    This   file   must  be  named
S:MRBackup.init.  With it, you may  set your desired defaults and
Flags.  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.


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, 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:src) 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.
Otherwise, 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).  I just didn't feel
the extra logic was worth it (I got lazy).

     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 only checked prior to  the  start of the next file copy












operation, so be patient if it does not respond immediately.

     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 (I wish they were distinct)
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.


Warranties

     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 you gonna' get  you  money  back?  Seriously, folk,
I've tested this beastie fairly thoroughly (I intend to USE it!),
but you know  how  things  go...there  may  be  a  bugaboo or two
lurking in there.  Please exercise  it a little before committing
your life (your precious data) to its care.














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 this
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:

     [e-mail]
     ...rayssd!galaxia!amanpt1!mrr

     or

     Mark R. Rinfret
     348 Indian Avenue
     Portsmouth, RI 02871
     401-846-7639 (home)
     401-849-8900 (work)


Changes Since the Last Release

     This section lists  changes  that  have  been  introduced in
version 2.0.  Though I will  attempt  to be thorough, some things
may slip through the cracks.  Please forgive any oversights.


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.