Testing of read access with Dosemu
==================================


I describe the method I use for my drives, you may need to change some names.
I have a DOS filesystem on /dev/hda1, I usually mount it on /DOS.
This drive is seen as c: from DOS when starting.
Stacvol file is c:stacvol.dsk. When config.sys is executed
stacvol.dsk is swapped and becomes c: and old c: is d:.

Prepare dmsdos package in /usr/local/src/dmsdos-x.y.z/src
  rmmod dmsdos      # for changes from next compilation
  make clean
  make
  insmod dmsdos
  cd /DOS
  mount -r -t msdos -o loop stacvol.dsk /mnt  # important: mount READ-ONLY!!!

Now you should see the root of your DOS drive in /DOS directory and
under /mnt the root of your stacker drive.
In the syslog you can see the parameters of all mounted stacker drives.
If you have dutil compiled, you can proceed the next test

  dutil /mnt checkfs

If there are errors you can see them in the syslog as DMSDOS: ...
Now you can make the read test.
Configure Dosemu for readonly access to the full hard drive or partition.

  disk { partition "/dev/hda1" readonly }  # must be first to boot from it
  disk { image "/var/lib/dosemu/hdimage" } # or something similar
	# you need this to have access to dosemu utilities

You must include somewhere in config.sys line

  device=<hdimage_drive>:\emufs.sys /

Now run Dosemu by command

  dos -C

If it does not work try to find out if stacker can see its stackvols.
There may be differences if you have some other organization of the drives
under DOS. 
Now you can see or change redirections to the Linux filesystem

  <hdimage_drive>:lredir 

For comparing you can use the dos utility cmpdisk.exe, which tries read all
files from two drives. One should be the drive managed by regular
dos stacker and the second by the Linux dmsdos driver.

  cd <stac_drive>:\
  cd <redirected_linux_drive>:\mnt
  cmpdisk <stac_drive>: <redirected_linux_drive>:

If some file is read differently from one drive, cmpdisk waits
for a keystroke. Then it continues. Parameters of cmpdisk can
be in form:

  <drive_letter>:[\]<directory>\ 

for example

  E:\mnt\

Any differences are suspected to be dmsdos bugs!