TROUBLE mounting your DOS partition?

TROUBLE mounting your DOS partition?

Post by /usr/people/georg » Fri, 03 Feb 1995 04:43:09


Some time back, I beseeched the Linux community to help me with a problem
I was having getting Linux to recognize my DOS partition.  I greatly
appreciate the inundation of help and responses I've received from various
individuals around the globe, so at the risk of being marked an ingrate, I am
compelled to respond with my findings - Thank you All!

if you try "mount -t msdos /dev/hda1 /dosd" for example, and you get the
ERROR: "wrong fs type, /dev/hda1 already mounted, /dosd busy or other error",
and your mount point (/dosd in this example) does exist, then you may be
experiencing the same problem I had.

On the other hand, if you get an error like this:
[MS-DOS FS Rel. 12,FAT 16,check=n,conv=b,uid=0,gid=0,umask=022]
VFS: Can't find a valid MSDOS filesystem on dev 0x0301
mount: wrong fs type, /dev/hda1 already mounted, /dosd busy, or other error

then it's most likely a problem with the DOS partition itself; the FAT is
probably too small for the size of the partition (i.e. it can't cover the data
area).  I came to learn about this from the e-mail responses I received, and
it seems to be the fundamental problem pointed out in most of them.  It was
further suggested to me by several people, that a bug in the kernel was the
culprit, and if I didn't want to try and patch it myself, then I would have to
resize the DOS partition either a little smaller or larger in order to fix the

I tried to patch the kernel, but got bogged down, and when I configured and
re-compiled the new kernel, version 1.1.81, it still didn't fix the problem.
I didn't relish the idea of having to delete my DOS partition, re-create it,
re-format it, and then re-load DOS; so instead, I ran FIPS
(see --> /pub/Linux/system/Install) which allowed me to split
my DOS partition into two partitions without loss of data.  The second
partition was very small (2.5MB).  This was just enough, however, to reduce
the size of my primary DOS partition to the point where it could be mounted
successfully by Linux.  

I found FIPS both reliable and efficient.  Granted, it's not as elegant as
patching the kernel, but it works!  Of course, it's a good idea to backup your
data and read all the documentation beforehand.  I'm not positive (forgive me
if I'm wrong), but I believe that DOS WON'T allow you to have more than 4
partitions, so if you currently have 4 (including Linux) partitions, and
you're experiencing the problem I had, then you may need to delete a partition
first before running FIPS.  If you don't do this, then when you run FIPS, it
will try to create a new one, and you'll end up with 5.  In my case, I had
one DOS partition and 3 Linux partitions, so I deleted one of my Linux
partitions, ran FIPS, which created a new 4th partition, leaving me with two
DOS partions and two Linux partitions.

NOTE: If you run FIPS, and you receive the error: "FAT too small", then try
re-running FIPS with the -osf option to override this.  This worked for me.

It was also suggested to me that Norton's Disk Edit might be a good tool to
use to patch up the problem; however, I didn't trust myself with that much
power since I'm not too familiar with the FAT file system!

I hope this helps.


1. how do i mount an extended dos partition or a dos logical partition ?

i need to access/share data with an NT machine (not on a network)
i have 10G removable hard drives
i am trying to put a file system on it to allow access by both linux and
linux won't mount an ntfs file system
the NT person put 4 primary (?) dos partitions on the disk
and if i run fdisk in linux it sees 4 FAT16 partitions
but it will only let me mount the first one

how do i mount the other 3 ?

is there some special way the disk needs to be formated by NT ?

thanks for any help,

2. doom question


4. NFS server

5. What partition sysid is OK for extended DOS partition mount?

6. PPP/ipfwadm problems

7. Trouble reading DOS partition - will fdisk help?

8. PGP for PINE and EUDORA

9. Some troubles with DOS partitions

10. Trouble preserving existing DOS partition during install of OS5

11. Trouble mounting dos part. to load Linux

12. Trouble with DOS mounted drives

13. Trouble mounting DOS w/ 1GIG? Read here..