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Text File | 1995-03-18 | 31KB | 570 lines

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.