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April 2002 [Newsletter Index] [Previous Page] [Next Page] [Feature Index] editor@os2voice.org

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

Introduction

The Server Edition of BackAgain/2000 is the flagship of Computer Data Strategies' (CDS), Inc. computer backup software. This Edition has the following features not found in the Workstation Edition:

1. Ability to backup HPFS386 access control lists;
   
2. Ability to backup JFS access control lists;
   
3. Supports autoloaders and changers;
   
   1. In order to support autoloaders (and changers), BackAgain must be equipped with an autoloader support module (asm) plugin, which must be purchased separately.
      
   2. An autoloader/library is a hardware device that can be loaded with multiple tapes or disks. Support for such devices allows BackAgain/2000 Server Edition to support virtually unlimited amounts of storage. For more details visit the web page BackAgain 2000/Autoloader Support Module.
      
   3. Note: Some autoloaders contain dual tape drives; in those cases the autoloader software module will operate both tape drives simultaneously!
      
   4. Disc autoloaders are often called "juke-boxes" or "changers".
      
   5. A relative newcomer to the mass storage scene is the DVD-RAM changer. These devices boost the maximum online storage capacity into the the terabyte range, and many are supported by BackAgain equipped with an ASM. If you are contemplating buying one of these devices, you should contact Computer Data Strategies support to see if it is supported by BackAgain, because the list on their web site is not always up-to-date.
      

4. Allows much larger (16 MB) backup and restore buffers for increased performance. The Workstation Edition, on the other hand, only allows a maximum of 4 MB buffers
   

Henceforth the term "BackAgain" will mean "BackAgain/2000 for OS/2 Server Edition, v.3a" unless otherwise specified. Moreover, the term BackAgain Workstation will mean "BackAgain/2000 for OS/2 Workstation Edition, v. 3a" unless otherwise specified. Where other variants of BackAgain need to be referred to, then additional qualifications will be included in the reference. Hopefully this convention will make this article a little easier to follow.

New Features

Here is a partial list of the new features introduced in V.3 (both Server and Workstation):

1. BackAgain now supports backing up to and spanning CD-R(W) discs.
   
   • To use this new feature, you must have the IFS bundle for RSJ CD-Writer, or a similar CDS-supported product, installed in your system. We'll discuss how to set up RSJ CD-Writer to engage this new feature later in the article.
     

2. Support for the newest tape drives on the market, such as LTO, SDLT, and Mammoth 2.
   
3. New command line backup and restore options that allow backing up or restoring from applications or batch files.
   
4. Now includes specific support for eComStation.
   

In this day of sky-rocketing postal rates and concern for our forests, few manufacturers distribute
paper manuals with their software products anymore. Paper has been replaced by onlinefiles. These files range from simple text files to HTML files to sophisticated Acrobat (.PDF) files with or without internal links. CDS is no exception to this general pattern. So the question of a software product's documentation these days is its amount, thoroughness, and quality. BackAgain/2 excels in this area:

1. Amount
   

   BackAgain has an IBM Information Presentation Facility (IPF) (extension. = .INF) file that documents its REXX library, an internal help file, a substantial introductory text file, and a large sophisticated Acrobat file with a Table of Contents and internal links. The total size of all these (mostly packed) files is close to 1,200 KB.
   

2. Thoroughness
   

   In version 2.0 several "holes" were apparent in both the internal documentation and the .PDF file. Several of these, especially those dealing with command line functions, appear to be plugged. However "holes" still remain. One particularly glaring one is the new "security file information". Since this is new, one would expect this to be covered in the documentation. Unfortunately, there is not a trace to be found, except a passing reference in the introductory Readme file.
   

3. Quality
   
   1. BackAgain's main documentation, the Acrobat file, is a pleasure to use compared to most PDF files.
      
      1. First, the display consists of two columns: the Table of Contents on the left, and the text on the right.
         
      2. Second, each line in the Table of Contents is linked to the section on the right that deals with the subject of that line.
         
      3. So using the main documentation file is largely a matter of clicking and reading: clicking on the item in the TOC that you need information about takes you immediately to the page in the main documentation.
         

   2. Again, I wish that more software documentation were this easy to use.
      

BackAgain comes in two basic forms: electronic (download) and CD. In either case the installation procedure is essentially the same. (I only wish more applications were as simple to install as BackAgain is!) With the electronic form, there is just one additional step:

You must create a directory for the BackAgain EXE file (different from the one you plan to run BackAgain from), copy or download the self-unpacking EXE file into this directory, and then execute the file.

1. If you have purchased the BackAgain CD, simply insert the CD into your CD-CDROM, double-click on the Install icon, and follow the on-screen instructions.
   
   • TIP: Unless you are really tight on disk space, you should probably click on "Select All". I have found that it doesn't pay to exclude some of the components, because the ones that take up most of the space are required, and because many of the components are interdependent.
     

2. Once the setup program has completed, you will see a message requesting that you reboot your computer. It's important that you do so, since much of the install actually takes place after the WorkPlace Shell (WPS) has been loaded.
   
3. Next, use the Window List (Ctrl-Esc) to see if the BackAgain Scheduler is running. If it is, right-click on it, and left-click on "Close".
   
4. Now download and expand the latest update to the product. As of this writing, it is located here. Unzip the file into a temporary directory, and follow the directions to apply the patch. According to CDS, the current patch fixes some tape spanning problems.
   

Configuring BackAgain/2000 Server Edition, v3

Before you can use BackAgain, you must (or at least you should) configure it. Doing this defines certain values that will always be used, unless you specifically set them otherwise in a SET (*.BST) file. Not configuring BackAgain can cause a great deal of confusion when you try to use it.

1. Drives Tab
   

   
   

   Note: for and the other screenshots in this article, click to expand image; then click on browser "Back" button to return to normal size.
   

   1. Open the BackAgain Folder and then double-left-click on "BackAgain/2000 Server" icon to start the BackAgain program.
      
   2. Click on "Configuration", located on the Main Menu.
      
   3. Select the "Preferences" item.
      
   4. This will open a window called "Drives".
      
   5. The "Help" button gives a clear and complete description of each option, so there's little point in repeating it here. I'll limit this discussion to some additional comments and tips.
      
   6. Since you purchased the Server Edition, you are probably running BackAgain on a network of some kind. In that case, the combination that usually works best is "Automatic scan" and "Scan neighboring servers".
      
      • This is also the most flexible setting, since it allows you to view all mounted drives on the network. Then you can select only the systems, drives, directories, and files you want from the tree structure map presented by the Backup and Restore windows.
        

   7. If, however, you are backing up a single workstation, then it's probably best to check "Automatic Scan". This will present all, mounted, local drives for backing up.
      
   8. However if there are some local drives that you never want to back up, for example your swap drive, you can use "Custom scan" to omit them permanently from the backup menu.
      

2. Backup Tab
   
   

   This page contains two sections:
   

   1. Default Backup Types:
      
      1. In OS/2, backups are controlled by the Archive attribute flag. This flag has the following significance:
         
         1. When a file is created or changed, the archive flag is set to "A".
            
         2. When the file is backed up using a full back up or incremental back up, the archive is cleared (or reset) to "blank".
            
         3. Special utilities, such as "attrib" and "FileStar/2" are able to manipulate the archive flag directly. Generally, this is not a good idea unless you have a thorough understanding of what you are doing.
            

      2. The OS/2 relationship between the attribute flag and backup programs produces four logical types of backups. These types are based on how BackAgain/2 (or any backup program) handles the Archive attribute flag. Here are the four types:
         

         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.

      3. BackAgain always resets the archive flag after the back up operation is complete, which makes it much easier to recover from a failed or partial back up. Some backup programs, such as BackMaster reset the archive flag on the fly, making recovering from a failed backup often next to impossible.
         

   2. Default Software Compression
      
      1. Select your choice of speed vs. amount of space used. Note: this is software compression, i.e. compression done by the processor, and is entirely different from any built-in hardware compression your tape drive may do.
         
      2. Here are the possible options:
         

         Maximize Speed	Balance speed and size
         Maximize Capacity	No compression

      3. Some tape drives with built-in hardware compression, such as many 4mm DAT drives, specifically require that you set your backup program to "No compression", so check your drive manual before making your choice.
         

3. Restore Tab
   
   

   On this notebook page, specify the action you wish BackAgain to take when a file with the same name exists both on the source and destination devices.
   

4. Buffers Tab
   
   

   This notebook page allows you to tailor BackAgain's performance for your system.
   

   1. If you don't care if BackAgain takes up all or most of the system resources while backing up, then slide the "Buffer size for backup operations" slider toward the right. If, on the other hand, you want to be able to use the system for other tasks (e.g. print spooling) then keep the slider toward the left to leave resources available for the spooler, which requires considerable resources to function at peak efficiency.
      
   2. Set the "Buffer size for restore operations" in the same manner, remembering of course that it applies to restores.
      
   3. Ultimately the best settings for these sliders will have to determined by trial and error.
      

5. Priorities Tab
   
   
   • This page contains another pair of sliders to control the relative responsiveness of the system vs. BackAgain throughput. However these sliders directly manipulate system priority variables, and therefore may affect the behaviour of the system more profoundly. Therefore the user is advised to move these sliders only a small amount at a time so the impact on the system can be assessed in small increments.
     

6. Tape Tab
   
   
   1. MTF (Microsoft Tape Format) Options
      
      1. Used for both reading and writing
         
      2. Should not be changed unless recommended by CDS, Inc. technical support.
         

   2. CTF (CDS Tape Format) Option
      
      • Used to read tapes created by BackAgain/2 for OS/2. User may specify the block size and QFA parameter.
        

   3. Warning: I have found that changing the block size between backup sessions often renders an entire tape unreadable until a long erase ("Wipe") is performed!
      

   4. Therefore, in the absence of specific instructions from CDS Inc technical support to the contrary, the settings on this page should NOT be changed.
      

7. Messages Tab
   
   

   Message Display Options
   

   1. Sound alarm when message is displayed (yes/no)?
      
   2. Pause on errors
      
      1. Wait indefinitely for operator response (yes/no)?
         
      2. Default response delay? (30 seconds)
         
         • This default may be changed by typing in a different number.
           

   Message Logging Options
   

   1. Log all errors and warnings (yes/no)?
      
      1. Use backup set logfile (yes/no)?
         
         • This option will append the messages to the Backup Set file.
           
      2. Other: [specify filename]
         
      3. Limit size of logfile to KB. [specify KB]
         

   Which combination of these options you choose is essentially up to you. You can try a few combinations and see which suit your personal preferences and your system best. As a start, here is the setup I use:
   

   • Sound alarm when error message is displayed;
     
   • Log all errors and warnings;
     
   • Log to file called "Messages.log"
     
   • Limit size of log file to 64 MB.
     

8. Misc. Tab
   
   

   This notebook page contains three final settings that need to be looked at.
   

   1. Display directory names only
      
      1. This simple option can be set on or off. However it can have a significant impact on your backup's performance. Here's how it works: if your backup consists of a lot of small files, the BackAgain can actually spend more time displaying each separate filename that it does backing up the files!
         
      2. If this turns out to be the case with your backup, then turning this option on can substantially improve the throughput of your backup. As with some of the other options, the only way to tell for sure is to experiment with your system.
         

   2. Default device
      

      Although the output device can be defined in each SET (*.BST) file, BackAgain gives you the opportunity here to define the device you use most often.
      

      1. Either enter the device, path, and filename directly into the window; or
         
      2. Click on "Change". This will open a window with a series of device types, including tapes, disks, and floppy diskettes.
         
      3. Select the type associated with your usual output device, and a number of options will appear in the "Options" window. These options will depend on the type of device selected. Choose the ones you wish, and click on "OK".
         

   3. Autoloader configuration
      

      I do not have an Autoloader and so could not test this feature. Instead I simply get the message "Autoloader support not installed". However I understand that if the Autoloader software module plugin is installed, a whole set of options will appear in this place, allowing the user to configure his autoloader.
      

      Click on OK. This is very important. If you fail to do this, and simply close the window by clicking on the OS/2 or eCS close icon for example, all the changes you have laboriously entered will be lost.
      

Next month in the VOICE Newsletter, I'll continue this article on BackAgain/2 Server for OS/2. Please stay tuned! If you have any questions or comments about this article, you can contact me at walter.os2@rogers.com.

References: BackAgain/2000, version 3.0 Developer: Computer Data Strategies, Inc.- http://www.cds-inc.com/prodinfo/ba2kos2.html Price: Workstation Edition $99.00, Upgrade from v2.1: $79.00          Server Edition $199.00, Upgrade from v2.1: $149.00 Other links referenced:    RSJ CDWriter - http://www.rsj.de/stage/en/default.asp    FileStar/2 - http://www.filestar.com/pages/filestar.html    Back Master - http://www.msrdev.com/ Additional Reading: Article by this writer showing the importance of backing up.    Backup: Why and How? Part 1 - http://members.rogers.com/wfmetcalf/OS2_Treasury/Articles/1999/aa082599.html    Backup: Why and How? Part 2 - http://members.rogers.com/wfmetcalf/OS2_Treasury/Articles/1999/aa090199.html Series by writer detailing procedure for backing up a LAN.    How to Back Up Your Network, Part 1 - http://members.rogers.com/wfmetcalf/OS2_Treasury/Articles/2000/aa072600a.html    How to Back Up Your Network, Part 2a - http://members.rogers.com/wfmetcalf/OS2_Treasury/Articles/2000/aa080200a.html    How to Back Up Your Network, Part 2b - http://members.rogers.com/wfmetcalf/OS2_Treasury/Articles/2000/aa080200b.html    How to Back Up Your Network, Part 3 - http://members.rogers.com/wfmetcalf/OS2_Treasury/Articles/2000/aa080900a.html Excellent article by Hewlett-Packard outlining several backup strategies.    Developing a Backup Strategy - http://www.hp.com/cposupport/information_storage/support_doc/lpg50113.html#P24_4051

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