re: Strange disk problems

Hi, FreeDOS scandisk does only look good, it does not work. There
is another FreeDOS filesystem checker that does better, I think. I
personally prefer to use Linux dosfsck (pretty good) for this.

For defragging, the FreeDOS version refuses to work on harddisks
because it is only an experimental version. PC-Mag defragr should
work (cannot handle fat32 and runs out of memory if you have very
long directories, but does work quite okay apart from that). The
MS version only runs with the correct VERSION=... in (fd) config.sys,
and you should be careful with XMS EMS and UMB drivers in combination
with it.

If you use a cache: MS Smartdrv crashes and/or trashes data if you use
it with FDXMS or FDXXMS as far as I know, and using it with FD EMM386
is not recommended either. My LBAcache cache should show far less
compatibility problems, but it is less efficient (no write caching).
You can also try the free-for-non-commxercial-use DR nwcache driver.
By the way, my driver WILL copy data wrong to/from floppies of sizes
other than 1.44 MB, so if you use those, please do NOT enable the "flop"
floppy caching option.
I am planning to add dynamically changeable drive geometry to fix that
problem and to improver support for changeable harddisks. I am also
planning to improve support for changeable harddisks in general, and
to increase the maximum number of drives recognized from 4 to 8 (this
is about physical drives, not about partitions, and not about floppies
either: I currently support up to 2 floppy and 4 harddisk drives).
The update will take some time, because I am busy with my studies - I
think you will not hear too much about LBAcache in october.

I have a strange problem with defragging and similar software: Sometimes,
partitions lose the F0 FF partition id code at the beginning of the FAT
data. I think some Linux utility causes this. When I use a disk editor to
correct the id code, everything is fine again. If the problem is caused
by some DOS thing, it could be the reason for your "defrag utility refuses
to run" problem.

Over the "incorrect time": Seconds can be 0, 2, 4, ... 62, and minutes can
be 0 ... 63, hours 0 ... 31, days 0 ... 31, months 0 ... 15 - you guess in
what way time and date of a file can be "incorrect". Think of 25h62m10s.

You should be VERY careful trying to correct problems that only get worse
in the process. The REAL error could be something completely different,
for example your partition table containing overlapping partitions, your
drivers having some 0.5 / 8 / anything GB boundary problem, your tools
being designed for fat12/16 and short filenames while your data contains
long filenames or is a fat32 (28) partition, this kind of things. If you
have enough space and the right tools, you should copy an exact image of
the damaged partition before experimenting with disk editors and stuff.