From: cgates@netcom.com (Craig Gates)
Newsgroups: comp.os.os2.misc
Subject: Sensible Dynamic Disk Compression for OS/2
Date: 7 Apr 92 20:03:33 GMT
Article-I.D.: netcom.+aqjaqf.cgates
Organization: Netcom - Online Communication Services  (408 241-9760 guest)


***** I am posting this for a colleague of mine. Please respond to
***** him via email or USENET. His email address is
*****
*****           zeke@spop.navo.navy.mil
*****
####################################################################

It has been rumored that v2.1 of OS/2 will have some form of disk 
compression built-in.  Owing to the rather porcine size of OS/2, I dearly 
hope that this is true.  However, having purchased both Stacker (the HW 
version) and AddSTOR's SuperSTOR, I hope that IBM is going to be a little 
more reasonable about how it provides disk compression. 
   
Both Stacker and SuperSTOR provide a completely inadequate method for 
compressing floppies.  Stac, in order to preserve the arrangements made 
with various third-party backup companies, does not allow multi-volume 
compressed floppies (i.e., one cannot use Stacker to compress floppies for 
a backup program).  SuperSTOR, on the other hand, allows this, but requires 
that all floppies be formatted and "prepared" first. 
   
I would like to see IBM provide as part of v2.1 a first-rate disk 
compression package which allows me to assign a floppy drive (e.g., A:) as 
a compressed drive (e.g, H:).  From that point on, any reading/writing to 
drive H: would be treated as compressed (although the physical drive would 
be drive A:).  The pudding test is that I could copy a file from A: to H: 
and the system would ask for the diskettes to be swapped, just like A: and 
B: in a single floppy DOS system. 
   
If the system detects that the diskette is not formatted, I would be 
allowed to format H: rather than A:.  This way, I would be able to tell my 
backup program that H: is my floppy, secure in the knowledge that all of my 
stuff would be compressed as it is put on the drive. 
   
SuperSTOR goes to a whole bunch of grief to create "packages" on the 
diskettes so that they can be recognized as compressed diskettes.  The side 
benefit of this is that it is impossible to format "on the fly".  A real 
feature. 
   
The primary reason I have for wanting compression of floppies in this way 
is not for routine backup, but rather for off-line archiving.  I use an 
excellent product called Maxi-Cat (from Maxi-Soft in Northern CA) which is 
analogous to the type of archiving provided by mainframe products. 
Maxi-Cat allows me to move files (based upon a number of criteria) off of 
my hard disk to floppies.  Maxi-Cat then leaves a null-length file in place 
of the original and marks its timestamp with a funny notation. 
   
When I then reference the file, either as an executable, data or overlay, 
the Maxi-Cat TSR interrupts the reference and, depending upon options, 
either loads the file back to the hard disk or allows it to be referenced 
directly on the floppy.  With this tool, I have the benefit of having my 
old records online without consuming all of the space.  As Maxi-Cat is now, 
I do not have the option of compressing the off-line diskettes. 

Therefore, I must write files from a compressed hard disk to uncompressed
floppies.  This is a huge waste of space.  By providing floppy
compression as a seamless operation, I can be executing a program on C:
(the hard disk) which is reading a data file on A:.  Upon encountering a
  certain piece of data, the program invokes a rarely used overlay which
is normally off-line.  The TSR (or driver) intercepts the request, asks
that the diskette containing the overlay be put into H: (the compressed
version of A:), the overlay is reloaded, the system requests that the
original diskette be placed back in A: and the operation continues.
 
This is just what one should expect...  I've heard whining from both Stac
and AddSTOR about how this cannot be done.  Bushwah!  Years back, when I
moved from CP/M to DOS, I purchased a program for the PC called UniForm
from some firm in deKalb, IL.  This program uses a device driver which is
configured for the specific format of the CP/M diskette (remember, they
were all different!).  I could then copy files from the CP/M diskette to
the DOS format diskette using only one drive.  The driver assigned
another drive letter to the CP/M device and the swapping of diskettes
worked just fine...  
 
Could someone please tell me how I can get this request to the OS/2
developers?  I dearly do not want them to come up with the wrong solution
as both Stac and AddSTOR have done...

Mike Hagerty