would it work to put an "unmount" button on USB flash devices?

[dpopiz]

is it possible to make a button on the USB device unount it from the OS? or is that something that has to be invoked by the normal user interface?

if it is possible, that would be really handy. just depress the button and pull it out.

 

[vetteguy]

Why? With 2000/XP/etc you can just pull the drive off and it unmounts automatically. The only thing that would cause a problem is if you were in the middle of a transfer.

 

[dpopiz]

you can't with 2000 and a few other OSes and in any case I'm pretty sure it doesn't actually *unmount* it. in XP I think it just suppresses the unsafe removal dialog if it's storage device. (and write caching is disabled for USB mass storage devices in XP, which helps)

anyway, I'm sure it's not actually unmounted when you pull it out and if it's not unmounted, it's not safe.

 

[ViRGE]

I digress, if it's not writing anything, it's safe. The file system will be fine, and since there isn't any data to be written, everything must be there, so what's the problem?

 

[dpopiz]

Originally posted by: ViRGE
I digress, if it's not writing anything, it's safe. The file system will be fine, and since there isn't any data to be written, everything must be there, so what's the problem?

but what if it is writing something?
that's the point. when you unmount something, all pending operations are finished up ASAP. maybe that's not a big problem for XP since it doesn't do the write caching. but elsewhere it's a big problem.

 

[ViRGE]

Originally posted by: dpopiz

Originally posted by: ViRGE
I digress, if it's not writing anything, it's safe. The file system will be fine, and since there isn't any data to be written, everything must be there, so what's the problem?

but what if it is writing something?
that's the point. when you unmount something, all pending operations are finished up ASAP. maybe that's not a big problem for XP since it doesn't do the write caching. but elsewhere it's a big problem.

If it's writing something, you don't yank it, it's as simple as that. An unmount doesn't force anything to go any faster, it's simply an extension of the eject idea for network volumes, which was extended from the idea to simplify getting rid of disks in MacOS(make the user do it, instead of making the OS do costly checks for the disk). Floppy drives didn't have this problem(PC at least, they were a bit smarter in this respect), and other than the larger size, that's all that a pen drive is; most even have the little activity light.