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January 2003

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BackAgain/2000 Server Edition version 3.0 - A Review, Part 5

By Walter Metcalf© January 2003

Note: This article is based on an earlier article on the same topic written by the author for However, the content has been substantially revised and updated.


After several months of looking at relatively straight-forward BackAgain/2000 operations, we are ready to examine an area where BackAgain/2000, especially the Server Edition, manifests some of its real power: backing up a complete LAN with one command.

  1. The Backup Cycle consists of a single Full Backup of the LAN plus a series of Differential Backups.

    1. Typically the Full Backup is run at night, once every two weeks to a month, depending on your needs and your tape inventory. It's important that all PC's be online to OS/2 when this is run so you need to either check the PC's yourself or appoint someone else to do it. Making signs asking people not to touch the machines during this time may help as well, especially if you have night-owls around.

    2. The Differential Backup should be run nightly (or more often if required.) This can be run safely along with a minimal amount of network activity.

  2. Preparing a Set of Backup Media.

    1. Before beginning your backup cycle, you need to prepare a set of labelled tapes (or alternative media. See Figure 1 below for a summary of the wide variety of backup devices supported by BackAgain/2000 for OS/2). You need two sets (sometimes called father-son) at the very least. Personally I don't feel safe unless I have at least three sets (grandfather-father-son), and I'm much more comfortable with four.

      Supported Backup Devices
      Floppy Drives SCSI Hard Drives (local & remote) Tape Drives (Travan, DAT, DLT, etc.)
      Local ATAPI Hard Drives USB Hard Drives (1.1 & 2.0) Tape Changer Systems (aka libraries)**
      Remote ATAPI Hard Drives Writeable CDR Drives (CDR/W)* CDR/W Changers (Jukeboxes)**
      Jazz Drives Zip drives
      Figure 1.


      1. Drives marked * required either CDS's IFS bundle or CD-Writer for OS/2 from RSJ.
      2. Drives marked ** require the additional CDS product: Back Again/2000 Autoloader Support Module

    2. The number of tapes in each set will depend on how big and how many disk drives you have and on which tape technology you are using: e.g. TRAVAN, 8mm, DAT, etc.

      1. A new technology has come onto the market recently--one with which you may want to experiment if you have a large disk file base to manage. I am referring to the Ultra-large IDE hard drives. Some of these monster-disks boast as much as 200 gigabytes with an 8 MB on line cache! These drives are available at a reasonable price.¹ (In addition some manufacturers are putting USB interfaces and external cases on them.) Such a drive holds far more data than any tape or collection of tapes within the budget of any SOHO user.
      2. It is also worth noting that the upcoming version of BackAgain/2000 for OS/2 v. 4 to be released in the spring of 2003 will no longer have the 2 GB maximum file limitation found in current versions of BackAgain/2000, making BackAgain/2000 v4.0 a perfect tool for backing up onto these huge drives.

    3. You should give some thought on where you want to store the Differential Backups. The setup described in this article appends them to the end of the Full Backup, continuing onto other tapes as necessary. This minimizes the number of tapes required. However some people prefer to keep the Full Backup on tape(s) by itself and keep the Differential Backups on a different set of tapes completely. Still another approach would be to put the full backups on CDR's, since CDR's have much more capacity than most tapes, and then put the differentials on tapes.

  3. Starting the Backup Cycle

    1. Make sure all PC's on the network that you wish to back up are online to OS/2-eCS, are idle, and will be left idle for a sufficient time to complete the backup.

    2. Close all applications except any required to support your network, such as InJoy Firewall.

    3. Make sure all PC's on the network have the shares defined for the drives you wish backed up and that they are on line. If you wish to verify which PC's are online you can type the following command from any OS/2 command prompt:
      NET VIEW

      This will return a list of all the computers the local PC can see. If one of the network computers you wish to back up is missing, try shutting it down, powering it off for a few seconds, turning it back on and restarting OS/2. If that fails, further investigation is required, and you may have to skip that PC for now.

      Trap: The Configuration | Preferences | Drives option "Scan neighboring servers" is very useful--so much so that I always leave it checked. However if this option is selected and you want to backup a remote workstation R from your main system M, do not have M connected to any drives on R. Otherwise any selected drives will be backed up twice.

    4. Open the BackAgain/2000 folder and then open the Sets folder;

    5. Drag-and-drop the FULL_LAN icon on top of the BackAgain/2000 program icon in the parent folder.

    6. When the main BackAgain/2000 Workstation window appears, click on "Start".

    7. When the Change Volume window appears, insert the first volume of one of your tape sets in the drive.

    8. Make sure the "erase media" box is checked, and click on "OK".

    9. The Backup will now start and run until all files on the Network have been backed up.

  4. Creating SET Files.

    SET files are a crucial part of BackAgain/2000's operational philosophy, so it is appropriate to pause here and review how to create them.

    1. Start BackAgain/2000, and click on the Backup button. This will open the Main Backup window. After a short pause, a list of the PC's on your LAN will be displayed in the left window. The current machine will be expanded and all the drives will be listed. See the screenshot below:
      Initial Lan Screen

      Figure 2. (Click on image to expand to full size.)

    2. Wait until the list of PC's has appeared in the left column, and "Ready" has appeared in the third window of the status line at the bottom before proceeding further.

    3. To create the FULL_LAN set, proceed as follows:

      1. Click on Set | Device from the Menu line, and then select the device to which you are backing up. If necessary, fill out the Path window using the Browse button. For more details on selecting alternate devices such as CDR's and hard drives, please see the second article in this series. Click on Cancel.

      2. Click on Set | Compression from the Menu, and choose the desired compression factor. Note: some tape drives have built-in hardware compression, and in such cases it may better to set the BackAgain/2000 compression to: "Do not Use Compression". Eventually, trial and error is the only way to determine what works the best in your situation.

        • TIP: It may be possible to temporarily disable hardware compression. My system uses a SONY SDT 9000 SCSI DAT drive, and on selecting the tape drive device, BackAgain/2000 displays a window containing a check box option identified as "Use hardware compression". This option is selected (ON) by default. I did some testing, and deselecting the option does make a huge difference in backup speed and time. Check your system to see if this option is available.

      3. Click on Set | Backup Type | Full to request a full backup. See the chart below for the different types of backups and their characteristics:

        Types of Tape Backups
        Full All selected files are backed up.
        files marked as backed up.
        Copy All selected files are backed up;
        does not mark files as backed up.
        Differential Backs up only selected files that have changed since last full backup;
        files not marked as backed up.
        Incremental Backs up selected files that have changed since last full or incremental backup;
        files marked as backed up.
        Figure 3.

      4. Check the remaining Menu options to make sure they are set the way you want.

      5. Finally, click on File | Save As from the Menu, and then enter FULL_LAN.BST. (Note: the BST extension is not strictly required, but it is still recommended.)

      6. Click on Save.

      7. Now it is time to select the Devices and Files to be backed up. Before specifying Devices, you must expand all of the workstations. To do this, left-click on the plus sign (+) to the left of each PC in the Main Backup window. See Figure 2. The result will look something like this:

        Small Expanded LAN

        Figure 4. (Click on image to expand to full size.)

      8. Now right click on the tower icons appearing beside each PC name (or the workstation name itself), and then select "Include all volumes" from the pop-up menu. This turns on recursion, and ensures that every file in every subdirectory on every device on that workstation will be backed up. You should see a green checkmark appear over each disk folder on the workstation.

      9. Repeat the process for each workstation you wish to back up. When you are complete, the Main Backup screen should look something like this:
        Small Expanded Checked

        Figure 5. (Click on image to expand to full size.)

      10. Now verify that the bottom left window of the status line still says "FULL_LAN", and click on File | Save from the Menu.

    4. Creating a Differential Set file (DIFF_LAN) is now very simple.

      1. From the Main Backup window, click on File | Open. This brings up an OS/2 Combo box labelled "Open".

      2. From the combo box, select and load the file FULL_LAN you created in the previous section.

      3. Wait until "Ready" appears in the third window of the status line.

      4. Click on Set | Backup Type | Differential from the Menu.

      5. Click on File | Save as from the Menu. This opens a OS/2 combo box called Save as.

      6. Enter the filename DIFF_LAN.BST in the appropriate window, and then click on "OK".

  5. Running the Full Backup.

    1. Open the BackAgain/2000 folder, and then open the Sets folder. Drag-and-drop the FULL_LAN icon on top of the BackAgain/2000 program icon in the parent folder.

    2. When the main BackAgain/2000 Workstation window appears, click on "Start".

    3. When the Change Volume window appears, make sure the "erase media" box is NOT checked, and click on "OK".

    4. The Backup will now start and run until all the specified files on the network have been backed up.

  6. Running the Differential Backups.

    1. The differential backup can be run manually from the main system exactly like the Full Backup except that DIFF_LAN is used instead of FULL_LAN and "erase media" must be unchecked instead of checked. (The latter should already be set correctly from the Set file definition, but it is still a good idea to check.)

    2. Differential Backups, however, are usually scheduled by BackAgain/2000 and run automatically. There are at least two different ways to achieve this.

      1. Using the BackAgain/2000 Schedule Folder.
        --This appears to be the "normal" method as expected by CDS, and certainly the cleanest and simplest one.

        1. Open SET's folder and open Scheduler Folder.
        2. Grab the right edge of the Scheduler Folder, and pull it far enough to reveal the "Change" button.
        3. Drag-and-drop a shadow of DIFF_LAN icon into the Scheduler Folder.
        4. Click on the "Change" button.
        5. Click on the "Daily" radio button, and select the other options in that section according to the days you want to run the backups. Note that at least one day of the week or one short-cut button must be selected.
        6. Enter the time (24 hour clock) when you want the backup to run.
        7. Check that the BackAgain/2000 Scheduler program is running and that a shadow of that program is in the Startup folder.

      2. Using BackAgain/2000's Internal Scheduler.

        1. Open the BackAgain/2000 folder, and start BackAgain/2000.
        2. Select Configuration | Scheduler from the Main Menu.
        3. Click on the "Add" button.
        4. Click on the "Browse" button.
        5. From the Open combo box, select DIFF_LAN.BST.
        6. Select on "Run backup hidden" according to your preferences.
        7. Click on the "Daily" radio button, and select the other options in that section according to the days you want to run the backups. Note that at least one day of the week or one short-cut button must be selected.
        8. Enter the time (24 hour clock) when you want the backup to run.
        9. Click on "OK".
        10. Click on "OK" to return to the BackAgain/2000 main screen.
        11. Select File | Exit to close BackAgain/2000.
        12. Note that you still need to have the BackAgain/2000 Scheduler program running and a shadow of that program is in the Startup folder.

      3. Clearly I would prefer the former method because it is cleaner and simpler to set up. However, on my system at least, it is not completely reliable. Sometimes the backup will start on cue every day for months. Then, apparently for no reason it will just stop. Sometimes reinstalling BackAgain/2000 will get it going again. However it quit working a few months ago, and reinstalling did not reset the problem. So I am now using the internal scheduler. In my experience, that method has always been completely reliable throughout several versions of BackAgain/2000, even including BackAgain/2.

        I realize this could easily be a phenomenon unique to my system, so I am simply presenting both methods to give you the benefit of my experience, and to give you a choice in case you run into a similar problem.

That concludes my tutorial on backing up your network, and my series on BackAgain/2000. If you have any questions, please email me, and I'll do my best to answer them.

Walter F. Metcalf

¹At the time of writing, Western Digital has a 7200 rpm IDE hard drive with 200 GB and an 8 MB online cache for $379.99 at their online store. Substantial discounts are available at most computer supply stores.

Disclaimer: All links in this article were checked at time of writing to ensure validity. However due to the nature of the Internet, some links may become invalid with the passage of time.

BackAgain/2000, version 3.0
Developer: Computer Data Strategies, Inc.-
Price: Workstation Edition: $99.00US, Electronic Delivery: $95.00US Upgrade from v2.1: $79.00US, Electronic Delivery $75.00
         Server Edition: $199.00, Electronic Delivery: $195.00
         Back Again/2000 Autoloader Support Module (ASM) for Back Again/2000 Server: $199.00, Electronic Delivery: $195.00
         The above prices were in effect at the time of writing. For more specific information please contact the developer.

Other links referenced:
   Part I of this review -
   Part 2 of this review -
   Part 3 of this review -
   Part 4 of this review -
   RSJ CD-Writer for OS/2:

Additional Reading:

Article by this writer showing the importance of backing up.
   Backup: Why and How? Part 1 -
   Backup: Why and How? Part 2 -

Series by writer detailing procedure for backing up a LAN.
   How to Back Up Your Network, Part 1 -
   How to Back Up Your Network, Part 2a -
   How to Back Up Your Network, Part 2b -
   How to Back Up Your Network, Part 3 -

Excellent article by Hewlett-Packard outlining several backup strategies.
   Developing a Backup Strategy -

Walter Metcalf has written many articles on the use and usefulness of OS/2 and eComStation. He was widely known as the Guide for the " OS/2" site until its unfortunate plug pulling. Walter has served as President of VOICE and is currently the Co-ordinator of VOICE's Warp Doctor project You can read more of Walter's articles in the archives of the VOICE Newsletter and many of his previous articles at his personal web site

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