How to switch off caching for usb device when writing to it?

Question

I have problems transferring binary programs to a micro-controller prototype board when using ubuntu/kubuntu to mount the board via usb. With MacOS and Windows there are no problems. I have found the writing from Ubuntu definitely changes the written file. I suspect that the write caching is the problem. How can I disable it, or what else might be the problem.

Answer 1

Read this first: http://groups.google.com/group/linux.kernel/msg/8d1591196c0ae15e?pli=1
I am unsure if it is true or not.

You can try using hdparm to set the write caching feature to off at runtime. (You will probably need to run this after every boot or every time you remove and reinsert the device)

sudo hdparm -W 0 /dev/devicename

Please ensure you know the correct device name (sdb, sdc or so on).

You can find out the device name by running:

sudo fdisk -l

You can also edit /etc/fstab and add the mount options sync,dirsync however I am not very familiar with how /etc/fstab works with removable devices. I think they need a permanent mount point.