removable bit not set for portable USB hard disk.

Pierre Ossman drzeus-list at
Sun Oct 2 01:35:52 PDT 2005

Gilles Schintgen wrote:
> Hi,
> A friend of mine just bought a "Trekstor DataStation pocket", but simply
> plugging in and mounting fails in KDE. The reason is that pmount refuses
> the mount operation (checked in konsole) because the device is not marked
> as removable.

Most USB devices aren't removable. Not in the HAL sense of the word at
least. They are however hotpluggable, which the device is correctly
marked as.

* Removable: Media can be removed but device node remains.
* Hotpluggable: Media cannot be removed without making the device node

Removable devices in Linux are things like floppys and cdroms. Most
other things are hotpluggable.

> Now my questions:
> * How does HAL determine whether to set the removable bit?

For the most cases it is determined by the kernel. The driver will set a
flag stating if the device is removable or not.

> * Would it be possible to force all USB media (Flash, HDD, etc.) to have
>   this bit set?

It would, but it would be incorrect. Programs that look for devices that
are what we normally call "removable" should check both 'removable' and
'hotpluggable'. If the don't then they're broken.

> * What's the syntax of pmount.allow? I couldn't find any information on how
>   the entries should look like, and what possibilities it offers.

Can't help you with this I'm afraid since I do not use pmount.


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