Anyone know how to do this?
There is de-mounting for a USB connection to a PC but nothing for thumbdrives.
If you disconnect the thumbdrive, the tablet complains that you should demount the drive first.
Same problem on my Haipad, and apparently other tablets too. Seems the only "safe" way to unmount them is to power down/hibernate the tablet and unplug the USB flash drive. Otherwise just unplug it, ignore the complaint, and risk the potential data loss (which is really only a risk if you do it when the LED is flashing indicating drive activity).
I'm sure there is a umount command you could run in a terminal emulator on a rooted tablet too, but that sounds bothersome. Oh, and some tablets DO have an unmount option hidden somewhere in the Settings, or so I've heard. I guess go through and remember additional settings may be "hidden" unless you press the "Menu" button.
Here is what i do - this is the easiest way to safely remove any device that does not automatically by the OS.
1) Download GScript from Market
2) Add a new script with the following:
3) On your main screen/desktop, long press and add a "shortcut"
4) Scroll down to GScript and select it
5) Locate your script you just created and click on it.
Basically you are just creating a fast 1-click shortcut to your desktop to unmount whatever you want. You will need to know the mount-point location of whatever device you are using first. For example: I use an external SATA drive with my Kyros in my car for all my music. By default my FAT32 partition will mount to the "/scsi" folder on my kyros. So I would just run "umount /scsi".
You must be rooted and have SU access to do this. If you want to see a list of all your mounts, create a script with the following in it and run it: