
		     Frequently   Asked Questions 
			  #2 - March 1995 
			   Disk Manager 6.x
				    
Note: an asterisk (*) indicates changes from the last FAQ

  
* 1) When is the next version of Disk Manager due?
     
Disk Manager 7 is scheduled to release very soon.  The next
FAQ will detail the specific changes this new version offers.
  
  2) What is DDO?
     
Disk Manager 6.x employs technology called Dynamic Drive
Overlay (DDO).  Unlike previous versions, which loaded a
driver via config.sys, DDO is a pre-boot loader.  This means
that all the necessary code is loaded during the boot sequence
rather than through driver files.  As always, our drivers exist to
provide solutions to BIOS or DOS limitations. In the case of
DDO,  this driver allows access to the full capacity of the new
large IDE drives.
  
  
  *3) Why do I need Disk Manager?
  
The basic issue is that while current versions of DOS can
create a partition up to 2 gig in size, it can only do this if the
geometry of the drive (cyl x hd x spt) has less than 1024     
cylinders.
  
The maximum geometry that the BIOS (prior to translating
LBA) can work with is 1024 x 16 x 63. (This works out to 504
megabytes).   DOS, basically knowing that BIOS won't exceed  
1024 cylinders, doesn't feel it should have to either.  However,
DOS doesn't care about the head or sector per track (SPT)
count,  SCSI's have, for years, taken advantage of this by       
having their Host Adapters translate the heads and SPT higher
(which  reduced the cyl count below 1024).  This is called
track mapping.   Unless you have some type of technology
which can perform track mapping to translate the geometry so
that it appears to have less than 1024 cylinders, this is the most
capacity you will be able to partition. Ontrack's Disk Manager
software  performs this translation from a software perspective
for IDE drives. There are controller cards which can perform
the translation from a hardware perspective and newer BIOSes
which have the LBA (logical block addressing combined with
translation) function can perform the translation from a
firmware perspective.  (Note - not all LBA also has the
translation feature.  Some show the translation as a separate
feature (e.g. the ubiquitous "Large Drive" option) so have
it but don't indicate that is there.  Check with your
documentation to be sure that the there is translation at the
BIOS level).

There is also another issue which serves to further complicate
the situation.  In the early days of hard drives; capacity
depended on whether the drive was formatted or 
non-formatted.  The capacity of new drives was determined in
millions of bytes - when formatted, the capacity was
determined in megabytes.  The megabyte capacity was a
smaller number as you were dividing by 1024 instead of by
1000 (as you did with millions of bytes).  Manufacturers
continue to list the millions of byte capacity (even though most
drives are formatted at the factory these days).
  
The average 540 (+/-) drive is actually 540 millions of bytes,
which works out to about  515 megabytes.  This is using the
full geometry of the drive, which is 1048 x 16 x 63.  If you are
looking at the amount of drive that DOS can work with, you
are using a geometry of 1024 x 16 x 63 which works out to 528
millions of bytes or 504 megabytes.  You can expect to see
any of these 4 capacities, depending on which geometry your
utility (such as chkdsk) is using.
  
Disk Manager also provides the solution to not having the
correct type in the CMOS drive type table to describe a
particular drive.  Most BIOSes these days have auto-configure
options and User Definable Types (UDTs).  If however, these
options are not available to you,  then Disk Manager can allow
you to get full access to a drive that is not described in CMOS.
  
Finally, Disk Manager can be a very handy utility for resolving
specific problems.  Below are just two ways in which Disk
Manager can be a lifesaver:
  
	  While one typically does not want to low level an IDE
	   drive, there are times when you will need a tool to do
	   this correctly  (especially when someone has already
	   messed things up with the wrong tool - like the system
	   BIOS!).  Low leveling IDE drives is tricky because of
	   the way they translate themselves - physical parameters 
	   are needed for a low level.  Disk Manager is able to get
	   the correct parameters from the drive itself as well as
	   any other pertinent information.  
  
	  Another very good use for Disk Manager involves
	  CMOS.  Say that you lose CMOS and can't remember
	  how to reset your UDT.  You can use Disk Manager to
	  view the partition table and gather the information you
	  need for resetting CMOS.
  
     
  4) How does Disk Manager impact 32 bit disk access
      (32bda)?
  
Microsoft  followed the WD 1003 standard when developing
their 32bda driver (WDCTRL). This standard follows the
traditional BIOS limitations, including the inability to
recognize a drive over 1024 cylinders, 16 heads and 63 sectors
per track.  These parameters add up to 504 megabytes or 528
millions of bytes.   Because WDCTRL follows the WD 1003
standard, it can't address above 504 megabytes either.  Disk
Manager provides access to drives that are larger than 504 -
WDCTRL cannot work with these drives.   We wrote our
own 32bda driver (Ontrackw.386) which performs the same
function, but also knows how to work with these larger drives.
  
The first version of Disk Manager be designed for
Ontrackw.386 was 6.03.  Version 1.15 of Rocket will go out
and upgrade a Disk Manager 6.02 or below to be able to work
with the Ontrackw.386 (so you don't have to upgrade Rocket
AND Disk Manager).
  
The Ontrackw.386 driver for Windows version 3.10 and WFW
version 3.11,  is not compatible with some hard disk
configurations.  A typical error message would be:       
  
	  "The version of Disk Manager (DM) or Drive Rocket
	    software currently on your system is incompatible with
	    the Ontrack 32-bit disk driver. Refer to your Ontrack
	    documentation for more information"
  
This can be caused by one of the following:
    
	   1) Any drive translating to more than 1024 cylinders. 
	   This is common if your drive was installed using a 
	  version of Ontrack Disk Manager prior to version 6.00. 
	  Drive Rocket will not install the 32bda drivers if this
	  condition is detected.  Again, version 1.15 (or above) or
	  Rocket should overcome this problem.  
 
	  2) Any system BIOS or controller BIOS which performs
	  hard disk translation. This is common if you are using 
	  an IDE drive which is larger than 528Mb. Drive Rocket
	  will not install the 32bda drivers if this condition is
	  detected.  IDE drives larger than 528Mb installed using
	  Ontrack Disk Manager version 6.00 or later using the
	  Dynamic Drive Overlay are supported.
  
  
  
  *5) How do I install OS/2, NT, Xenix, NetWare (etc) on this
      drive?
  
Current versions of Disk Manager ONLY support DOS.  The
next major release of Disk Manager will allow dual-boot
systems.  If your drive is currently partitioned to its full      
capacity you could not nondestructively install the secondary
operating system.
 
The manufacturers of the various operating systems have also
worked towards making their products compatible with Disk
Manager:  

     OS/2 & OS/2 Warp:

IBM first developed a filter (.flt) driver which allowed some
OS/2 configurations to work with Disk Manager.  IBM next 
developed an adapter driver (IBM1s506.add) which provides full 
compatibility with Disk Manager 6.x.  This driver is part of 
the "FixPak" release of Warp.  (Please note, you will still need
to wait for Disk Manager 7 for OS/2 2.x)
  
     Microsoft NT

Microsoft's NT developers have created a "hotfix" for their
atdisk.sys file.  This modification will make NT fully
compatible with Disk Manager versions 6.x.  Version    
3.5.1 of NT contains this driver.  

     Windows 95

This operating system will be compatible with Disk Manager
6.x and greater "out of the box".

     Linux

Disk Manager 7 will be  compatible with Linux.  We have not had
the opportunity for extensive testing with LILO (the Linux boot
manager).  More on this will follow.  In the meantime, we do know
that LILO offers to install itself to several different areas in track 0.
You would definitely not want to let it install to the MBR. There are
no known fixes to provide compatibility for Linux with earlier 
versions of Disk Manager.
  
     NetWare

Current versions of Novell NetWare do not need Disk Manager
(or anything else) to access large hard drives.  NetWare 3.x
and above have the ability to auto-identify the drive and do not
have the 1024 cylinder limitation.  
  
   
  6) Disk Manager says my hard drive is not a BrandX, but it
       is!?
  
OEM versions of Disk Manager check for the specific OEM's
hardware.  If your Disk Manager came bundled with a BrandX
drive, for example, it starts by sending a "who are you and how
big are you" query.  If the response is anything but "Brand X",       
Disk Manager will produce an error message.  Some
sophisticated IDE cards will intercept queries and commands
sent to the drive.  In the case of my example, the card would
respond "the drive  is XXX meg and me? I'm Brand XYZ
Card".  This will cause Disk Manager to believe there is no
drive for the OEM, even if there is.  The only solution for this
is to obtain a universal (non-OEM) version of Disk Manager
that does not care who made the hardware.
  
  
  7*) How do I un-install Disk Manager?
  
The easiest approach is to run Disk Manager with a /y- (
(DM/y-).  This will reformat (to the limits of DOS) and
not install DDO. 

To repartition without DDO, boot clean from a floppy (no
config.sys).  Run DOS's Fdisk command and then the DOS
Format command. DDO will be completely overwritten.
  
PLEASE NOTE: Removing the DDO is destructive.  You must
backup your data before commencing.
  
  
  8) How come I'm getting a message that I am out of disk
      space after loading in 800 mb of data when I have a 1 gig
      drive?
  
In DOS, every file that is stored gets at least one allocation unit
(called a "cluster") no matter what the size of the file is.  The
size of the cluster grows incrementally with the size of the
partition.  If you have a 1.8 gig partition, the cluster size will
be 32k.  This means that even a 62 byte batch file is going to
consume 32k of storage space (the difference between the 32k
of the cluster and the 22 bytes that the file really needs is
called "slack space"). 
  
The only feasible way to reduce the cluster size is to reduce the
partition size.  The break down for DOS 4 and above is as
follows: 
  
     0 - 128           2k
   129 - 256           4k
   257 - 512           8k
   513 - 1 gig        16k
	>1 gig        32k
  
  9) How does Disk Manager use memory?
  
Ontrack's DDO (Dynamic Drive Overlay - the utility which
allows access to >504 mb)  starts by loading into conventional
memory, where it consumes 6k .  It then moves to take 4k of
upper memory, leaving behind a 62 byte "footprint"  at the top
end of conventional.  This can sometimes conflict with other
programs.
  
You can change how Disk Manager loads into memory in the
following manner:
  
During the boot process, when you see the message which tells
you to press the space bar to boot from floppy, press the <S>
key instead, and  then answer <Y> to the next question.  This
will cause Disk Manager to stay in conventional memory,
rather than moving to high memory and may resolve the
conflict you are experiencing.
  
If it does resolve the problem; we have a special version of our
drivers which will prevent you from having to hit the <S> key
every time you boot.  The file is called Loadlow.zip and can be
found on our BBS and in our CompuServe forum.
  
  10) I ran Disk Manager on my BRAND X drive and
	everything went fine.  When I tried to install DOS 6.2,  I
	ended up with a 504 meg drive.
    
After you format the drive with Disk Manager,  it is critical
that you load Dynamic Drive Overlay (DDO) into memory
before booting from a floppy.  It is required, for instance, to
boot from floppy to install DOS 6.2.  The procedure would be
as follows:
  
Boot from the hard drive.

When you see the "press spacebar to boot from diskette"
message,  press the spacebar Insert the diskette and "press any
key to continue"
  
The boot will proceed from the floppy, but DDO will have had
a chance to load into memory and the partitions will now make
sense (so the DOS install will not re-format)
  
   
  11) Everything was working fine after I installed Disk
	Manager, but this morning I got a "DDO Integrity Error"
	and I can't access the hard drive.
  
This message indicates that the sector containing the DDO
(dynamic drive overlay) information (at the front end of the
drive) has become corrupted.  This should be considered as
being the symptom of a greater problem, rather than as a
problem in itself.
	
This can be caused by:
  
	infection by a boot or partition sector virus (most
	common).  Boot from a clean DOS diskette and run a
	virus scan software.
  
	power surge
  
	hardware failure (drive or card)
  
	shutting the computer down in the middle of a write
  
	etc  
  
  * 12) How Does Disk Manager work with Enhanced IDE
	(EIDE/Fast ATA)?          
  
Current versions of Disk Manager do not fully support the
EIDE standard.  This standard covers 4 enhancements:
  
	Support of secondary controller
	Support for >504mb (528 millions bytes) 
	32 bit host transfers, Mode 3 or 4 transfers (PIO xfers)
	Non hard drive devices (e.g. IDE CD ROM)
  
  
Disk Manager currently supports the first two, but not the
second two.  (please be aware that 32 bit host transfers are not
the same as 32 bit disk access in Windows or WGFW.  We do
support Windows 32bda).
  
The next major release of Disk Manager will be fully
EIDE/Fast ATA compatible.
  
  13)  I can only get 16 bit file access in WGFW on the slave
	 drive I formatted with Disk Manager.  How can I change
	 this?
	
When Disk Manager is used to format the Master drive, the
DDO (dynamic drive overlay) is loaded during the boot
process, from the front end (non data area) of the drive.  In this
situation, there is no "device=dmdrvr.bin" line in the config.sys
file.
  
However, if Disk Manager is used to format the slave drive and
the Master was formatted straight DOS, there will be that line
in the config.sys and the DDO is loaded differently.  It is this
difference in how DDO is loaded that is causing the 16 bit file
access on the second drive.  The only resolution would be to
back up all the data on the Master drive and format it also with
Disk Manager.  This would cause the DDO to be loaded during
the boot process and allow 32 file access on both drives.
  
  14) Why are my drive letters all switched around?
  
DOS allocates drive letters every time you boot.  It starts first
on spindle 1, then goes to spindle 2 (3, 4 whatever) looking
first for primary DOS partitions and then for DOS extended
partitions.  When it has done this, it then allocates drive letters
as requested by drivers loaded in config.sys (CD-ROMs, us,
hardcards, etc). 
  
When you boot from the hard drive, DDO (dynamic drive
overlay) is loaded before DOS. This means that when DOS
looks at spindle 1, it can "see" that primary DOS partition and
gives it C.  It then goes to the second drive and allocates D.
  
When you boot from the floppy, the driver line in config.sys
(dmdrvr.bin) kicks off DDO - but this doesn't happen until
*after* DOS has already gone looking for primary DOS
partitions and assigned drive letters.  Because DDO wasn't in
memory when it looked at spindle 1, it did not see that
partition.  It did see the partition on the non-Disk Manager
spindle and that became C. Config.sys loaded our driver, which
kicked off DDO and asked for drive letters - DOS saw the
partition on spindle 1 and gave it the next drive letter, D
(whew!).
  
An easy way to avoid this is to start the boot from the hard
drive. When you see the "press spacebar to boot from diskette"
message, press the spacebar to halt the boot process and insert
your boot floppy.  The boot will continue on the floppy, but
DDO will have loaded and the drive letters will be allocated as
usual.
  
  
  15)  How do I create the floppy so that I can boot from floppy
	  and still have DDO load?
  
Follow the directions in the Disk Manager help section for
creating an Emergency boot floppy, or use DMCFIG.EXE
follows:
  
		      DMCFIG /d=a:
  
   answer <y> to the appropriate questions
  
  16)  Can I use "BRAND X" utilities on my hard drive?
  
The basic rule of thumb for us and utilities is that if the utility
in question goes through DOS (and int13) to get to the
hardware, it will see us and all will be fine.  If the utility goes
straight through to the hardware, there is the potential for data
corruption.
  
As it would be impossible for us to keep track of every rev of
every utility, we take the line of explaining the concept and
asking that you check with the manufacturer of the software
for compatibility.
  
  * 17) Can caching controllers cause problems with Disk
	 Manager?
  
Some caching controllers interfere with Disk Manager's ability
to auto-identify the hard drive. In this case, a list of model
numbers will appear.  Simply select your drive from the list
and continue as usual.  Alternately, you could disable the cache
temporarily while formatting the drive..
