Background
I have been a strong advocate of regular system backups for years.
Some of you may know I've written several articles on the subject. Over the recent
years, OS/2 users have had only one good choice for backup software -- CDS's Back
Again/2000 product family. However their latest version v.4 failed to provide for
backing up hard drives larger than 2 gigabytes.
With modern hard disk drives becoming so large and relatively
inexpensive, it is quite easy to get partitions that exceed the 2 GB limit--if only
because the number of letters is limited to 24. For example, on my main system,
I have 9 partitions that are larger than 2GB!
The failure of CDS to respond to the needs of users with large
hard drives can be partly explained, I suppose, by the fact that their software
line was developed for tape backup products, and their software has been expanded
to include backing up to hard drives and other products only recently.
As I continued to backup to tape, I began to find that the cartridges
for modern tape drives were expensive and were often not that reliable over a period
of time. Even 3-M has withdrawn its lifetime warranty for its data cartridges. Not
only that but it began to take more and more tapes to handle my full backups; and
multiple tape backups are a major source of errors--both human and machine. As hard
drive prices continued to drop, I did some math, and realized that large hard drives
were cheaper to use than tapes. In addition they were much faster and more reliable.
But I couldn't back up to my large hard drives because no software
would produce archives larger than 2 GB. So I was stuck! After letting my disk drives
go for many months without being properly backed up--which made me increasingly
nervous, I made the decision to write a software product for my own use.
However, I'm not a developer. Fortunately there is one
OS/2 software product that will handle partitions and archive files of any size:
RAR written by Eugene Roshal. Eugene is focusing his development work on Windows
version of RAR, but he is still making the OS/2 version available
from his web site. RAR does this by producing "multi-part" archives (i.e.
archives which consist of several smaller files). This operation is performed on
the fly, eliminating the need for special post-archive handling.
RAR for OS/2 is a solid, reliable disk backup program, but it
has a number of serious limitations, which make it difficult to use for regular,
unattended backup. To name just two, the OS/2 version does not handle (i.e. reset)
the archive flags and there is no differential backup feature--something I cannot
live without.
What is LDBkup?
LDBkup (Large Disk Backup) is
my attempt to get around the limitations in RAR. Essentially where I have seen bothersome
limitations, I have written code to perform functions to eliminate them. For example,
since RAR for OS/2 has no differential backup (at least not that I could find),
I have written supplementary REXX code to perform this function while still using
RAR. (Don't even ask!) Sometimes the code isn't the prettiest in the world, but
it does work.
Another major limitation in RAR is the awkwardness in the OS/2
version of handling several logical disk drives in a single session. If you're dealing
with very many hard drives, it gets very difficult to set it up. So I wrote some
code in LDBkup to make it a snap to backup all your drives (even 24!) in one session.
LDBkup should be considered a first-release beta. I have tested
as many combinations as I can, but there are hardware configurations that I don't
have, and I probably missed some things even with the hardware I do have. So useful
feedback would be appreciated. (Simply telling me it doesn't work is not considered
"useful". If you want to report an error, tell me as much as possible
about your hardware and software configuration, exactly what you were doing when
you got the error, and what the message is. Copies of the log files log.txt, err.txt, and fileslist.lst,
would help as well. These files can be found in the directory containing LDBkup.cmd.
Another cool feature about LDBkup is that it supports networks.
You can choose to backup to a local drive or to remote drive. For example, I have
one workstation containing three super-fast 120 GB hard drives linked together as
one huge LVM drive. LDBkup backs up to that monster drive without a problem.
Features
Installation
Installation is very simple. Just unzip the archive into the
same directory containing RAR.This directory can be any directory you choose. You
also need to rename the file named RAR32.exe to RAR.exe. LDBkup is delivered as
four files: LDBkup.cmd, LDBkup1.cmd, GettingStarted.txt (for the impatient among
us), and LDBkup.html (the file you're reading now and sometimes referred to as "the
manual".
LDBkup.cmd defines two values that the main program--LDBkup--needs
to know about. They are:
Important Note: If you wish to put the archives on a drive
on the same system from which you are running the backup, simply set LD_Output to
"\\" followed by the server name (this is usually the same as the
host name) of your system, followed by "\" and the share name
of the drive where you want the archives to go. You can learn the values of both
resource name and the share name by using the "Peer Workstation" utility,
and clicking on the "Connections" tab, and then on the "Create Connection"
button. This utility is located in the "Network Utilities" folder, which
in turn is located in the "Local Network" folder on your Desktop. (On
some versions of OS/2 or eCS, this utility may be called "Sharing and Connecting",
"Shared Resources and Network Connections" or something similar.)
Example: \\BackupComputer\CDrive
Networking Note
I have a fair size LAN at home where I work. It consists of 6
workstations, a cable modem, a router, a switch, a hub, a print server, and a laser
printer. My main desktop is connected directly to the router; however many of the
other workstations are connected to a switch or a hub which is an uplink from the
router.
When I first started developing LDBkup, I discovered that often
when attempting a back up to the remote workstation I was using, RAR would crash
(i.e. trap) with a network error. (I believe the error message reported the crash
as occurring in NetBios). After trying all manner of things, I eventually tried
replacing the NetBios protocol with NetBios over TCP/IP in both machines. Voila!
everything now worked. I have since replaced the NetBios protocol with NetBios over
TCP/IP in all my machines, and no longer experience this problem.
I recently discussed this problem with Ken Kirchner, VOICE's
System Administrator, author of eBayWatch/2,
VOICE's system administrator, network guru, and all-around nice guy. He asked me
what network cards I was using. When I told him that I had 10/100 Belkin cards which
use the Realtek 8139/8130/810x chip sets with the latest driver (Jan 2003), he told
me that this chip set works great with TCP/IP, but when used with NetBios under
heavy load, it can cause traps. (Ken suspects it's actually the driver that's at
fault, but this hasn't been confirmed.). My solution works because NetBios over
TCP/IP is an emulated NetBios that uses the TCP/IP transport protocols.
So, if you run into that problem, you have two possible solutions:
change your NIC's or replace the NetBios protocols.
Unfortunately, changing the protocols is sometimes not easy,
because the MPTS tool only does part of the job. Here are some pointers based on
my experience with my machines:
Once you've configured your system that way, things should
work properly. However, as always, your mileage may vary. You are welcome to email me if you have problems, and I'll
see what I can do to help.
1) LDBkup DIFF C: L: G: D:
a) For each drive shown, LDBkup backs up every file that has the Archive flag set on.2) LDBkup full e:
b) The archive flags are reset for each drive when the backup for a drive is completed successfully.
a) LDBkup performs a simple full backup on drive e:
b) The archive flags are reset for each drive when the backup for that drive is completed successfully.
Limitations
Future Plans
Requirements
Support
Licence
LDBkup is released as "copyright freeware". You are
granted a
license to use this program freely, but the copyrights to the program
and program code remain with the author. Distribution is allowed, as
long as there is no more than a token copying or distribution fee
charged. This program may not be released as part of any commercial
software program, suite or compilation.
THERE ARE NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
IF THERE ARE ANY RESTRICTIONS OF EXCLUSIONS OF IMPLIED LIABILITY IN YOUR JURISDICTION,
YOUR LICENSE TO USE THIS PROGRAM IS HEREBY REVOKED.
Walter F. Metcalf
walter.os2@rogers.com
5 March 2004