Category : HD Utilities
Archive   : DSKMON.ZIP
Filename : DSKMON.DOC

dskmon (disk monitor)
Version 1.00
Chris Dunford
The Cove Software Group

Purpose
-------

Dskmon is a small resident utility that monitors the activity of
your disk drives and allows you to track disk accesses and
errors. Dskmon records summary information for all significant
disk activity, and keeps detailed records of disk errors.
Dskmon supports physical disks only (no RAM disks), and only
those disks for which basic service is provided by the PC's ROM
BIOS.


Installation
------------

To install dskmon, simply execute the program with its one
optional argument:

dskmon [n]

The optional argument is a decimal number that specifies the
maximum number of errors for which detail records will be kept.
This number defaults to 100, but you can set it to any value
from 10 to 1000. For example, to specify 200 error records:

dskmon 200

When dskmon is installed, a resident "kernel" is left behind;
this kernel consists of the disk activity monitor and dedicated
memory space where the error records will be stored. The size
of the kernel depends in part on how many error records are to
be kept. Dskmon will reserve approximately 900 bytes of memory
for general code and data, plus 12 bytes per error record, plus
a copy of your current DOS environment.

For example, with a 100-byte environment and 50 error records
(installed as "dskmon 50"), dskmon would require about 900 +
(50*12) + 100 bytes for the kernal, or about 1.5K bytes of
memory.

If an error occurs and the error record list is full, the oldest
error record will be deleted.


Drives monitored
----------------

Dskmon monitors drives that are identified to BIOS by drive
numbers 00 to 03 (floppy drives) and 80h to 83h (fixed disks;
standard BIOS supports only fixed disks 80h and 81h, but dskmon
also watches for drives 82h and 83h in case you have an
extension to BIOS installed).

In a typical configuration, floppy 00 represents drive A, floppy
01 represents drive B, and so on. Fixed disk 80h is the first
fixed disk (drive C, if you have two floppies), etc.


Status displays
---------------

To obtain information about disk activity, run dskmon again. It
will extract data from the resident kernel and display the
information you ask for. The exact syntax is:

dskmon [CLEAR] [SUMMARY | ERRORS] [drivelist]

Note that all of the parameters are optional, so the simplest
command is simply:

dskmon

which will display summary information for all drives that have
been accessed, as well as a list of all recorded errors. The
display format looks like this:

Drive summaries (errors/attempts):

Drv Read Write Verify Format Other
--- ---- ----- ------ ------ -----
01 3/3 0/0 0/0 0/0 0/3
80 0/98 1/24 0/0 0/0 0/0

Error detail list:

Operation Cd Time Drv Cyl Hd Sc Er Description
--------- -- -------- --- --- -- -- -- -----------
Read 02 15:16:10 01 0 0 2 80 Device timeout
Read 02 15:16:13 01 0 0 4 80 Device timeout

The first section ("Drive summaries") presents summary
information for each drive that has been accessed since dskmon
was loaded. For each drive, dksmon shows the number of reads,
writes, verifies, formats, and "others" (anything else). For
each type of operation, two numbers are shown; the first is the
number of errors, and the second is the number of attempts. For
example, drive 80h (first fixed disk) shows no errors in 98 read
attempts (0/98) and two errors in 24 write attempts (2/24).

The second section is a detail list of all recorded errors. For
each error, the following fields are displayed:

Operation Operation name (read, write, etc).
Cd BIOS operation code (Int 13h reg AH)
Time Approximate time of failure
Drv Drive number (hex)
Cyl Cylinder number (track)
Hd Head number
Sc Sector number
Er BIOS error code (hex)
Description Description of error

See below for a complete list of error codes and descriptions.

Naturally, dskmon displays can be redirected to disk if you wish
to create a text file containing the summary/error information:

dskmon > errs.txt

NOTE: floppy disks may generate occasional read errors due to
reads attempted before the motor has come up to speed. If you
do not see any error messages from DOS, but dskmon reports some
read errors, this is probably the cause (DOS will re-try the
operation several times before reporting an error). This type
of error is not a matter for concern.


Displaying summary only or errors only
--------------------------------------

If you wish to see only the summary data, add the optional
parameter SUMMARY:

dskmon summary

If you wish to see only the error records, add the optional
parameter ERRORS:

dskmon errors

All of dksmon's optional parameters can be abbreviated to any
number of characters. Thus, s, su, sum, summ, etc., are all
valid parameters. For example,

dskmon s

can be used to display the summary only.


Clearing records
----------------

You can clear (zero) any of dskmon's data by using the optional
CLEAR parameter; this may be followed by either SUMMARY or
ERRORS to selectively clear either of those records. For
example:

dskmon clear [Clear everything]
dskmon clear errors [Clear all error records]
dskmon clear summary [Clear summary records]

Again, these may be abbreviated:

dskmon c e
dskmon cl sum


Selecting drives for display/clear
----------------------------------

Any dskmon command can be followed by a list of drive numbers.
If present, information will only be displayed or cleared for
the selected drives. For example:

dskmon 80 Display all, drive 80 only
dskmon 0,80 Display all, drives 0 and 80
dskmon summary 0,1 Display summary only, drives 0 and 1
dskmon errors 80 Display drive 80 errors only
dskmon clear 80 Clear summary/errors for drive 80
dksmon c e 1,2 Clear drive 1 and 2 error records
dskmon cl sum 81 Clear summary data for drive 81


BIOS error codes
----------------

All error codes are hexadecimal:

01 Bad command (unsupported BIOS function)
02 Address mark not found (media error)
03 Write protected
04 Sector not found (media error)
05 Reset failed
07 Drive param set failed (unable to set drives parms in ctlr)
08 DMA overrun
09 DMA boundary error
0A Bad sector flag found
0B Bad track
10 CRC/ECC error (media error)
11 ECC data corrected (media error, corrected)
20 Controller failure
40 Seek error
80 Device timeout
AA Drive not ready
BB Undefined error
CC Write fault
E0 Status error
FF Sense fail

Revision history
----------------
Version 1.00 - 10/4/86
Original version


Copyright/License/Warranty
--------------------------

This document and the program file DSKMON.COM ("the software")
are copyrighted by the author. The copyright owner hereby
licenses you to: use the software; make as many copies of the
program and documentation as you wish; give such copies to
anyone; and distribute the software and documentation via
electronic means. There is no charge for any of the above.

However, you are specifically prohibited from charging, or
requesting donations, for any such copies, however made; and
from distributing the software and/or documentation with
commercial products without prior permission. An exception is
granted to not-for-profit user's groups, which are authorized to
charge a small fee (not to exceed $7) for materials, handling,
postage, and general overhead. NO FOR-PROFIT ORGANIZATION IS
AUTHORIZED TO CHARGE ANY AMOUNT FOR DISTRIBUTION OF COPIES OF
THE SOFTWARE OR DOCUMENTATION, OR TO INCLUDE COPIES OF THE
SOFTWARE OR DOCUMENTATION WITH SALES OF THEIR OWN PRODUCTS.

THIS INCLUDES A SPECIFIC PROHIBITION AGAINST FOR-PROFIT
ORGANIZATIONS DISTRIBUTING THE SOFTWARE, EITHER ALONE OR WITH
OTHER SOFTWARE, AND CHARGING A "HANDLING" OR "MATERIALS" FEE OR
ANY OTHER SUCH FEE FOR THE DISTRIBUTION. NO FOR-PROFIT
ORGANIZATION IS AUTHORIZED TO INCLUDE THE SOFTWARE ON ANY MEDIA
FOR WHICH MONEY IS CHARGED. PERIOD.

There is no restriction on the use of this software in
commercial or institutional environments.

No copy of the software may be distributed or given away without
this document; and this notice must not be removed.

There is no warranty of any kind, and the copyright owner is not
liable for damages of any kind. By using this free software,
you agree to this.

The software and documentation are:

Copyright (c) 1986 by
The Cove Software Group
Christopher J. Dunford
10057-2 Windstream Drive
Columbia, Maryland 21044
(301) 992-9371