Issues mounting USB drive - QNX 4.25


Using the steps in the article posted below, I am able to mount a USB thumb drive (2.0) successfully.

However, I am not able to mount a USB drive other than the thumb drive. I’ve tested with drives from three different manufacturers and get the same message each time:

“…no DOS devices found in auto-scan of /dev”

A Google search hasn’t led me anywhere. Does anyone have any ideas/suggestions for me?


Just guessing here.

I assume that these other USB drives do have DOS data on them, right?
Is it possible that they have NTSF rather than FAT partitions?
QNX 4 cannot read an NTSF partition.
I don’t think QNX 6 can either.

There’s also exFAT which QNX 4 probably can’t read.

The thumb drive is NTFS and I was able to read and write to it this morning. This afternoon, I am now not able to even mount the thumb drive. I’ve rebooted several times and followed the same steps as I did in the morning. Very odd.

With regard to the larger external USB drive, it was also formatted NTFS. I am reformatting it as FAT and will try again.

Thanks for the input.

I was wrong - the filesystem on the thumb drive is FAT, not NTFS.

Okay…I formatted the external drive as FAT32 format and re-ran drivers and mount command as follows:

./bin/io-usb &
./bin/Fsys.umass &
./bin/Fatfsys &

The above run without any issues/ I see /dos, however it’s empty.

When I run “df -a”, I see an entry:

? 156290904 ? ? ? ?% /dev/hd1

There could be a limitation on the partition size. Sorry I don`t know what it is.

That’s what it looks like to me. You might try putting a smaller partition on the device to see if that helps. If it does, you probably will need to use multiple partitions if you need the entire space.