Possible solution(s) discussed here:
OMG! Ubuntu > Connect your Android Ice Cream Sandwich Phone to Ubuntu for File Access
As explained by Google Engineer Dan Morrill, the USB mass storage protocol was a block-level protocol. What this meant was that a partition could not be mounted on two different systems at the same time. Each partition that needs to be mounted on a computer must be unmounted from the phone first. This would be impossible on a phone with only a single partition, since if the system partition was unmounted, the phone would crash.
To work around this issue, Android phones up until now either had two partitions in the internal memory (like the Nexus S) or had a microSD slot (like the Samsung Galaxy S II). Phones with micro-SD slots would just export the microSD card partitions to the connected computer.
But the Galaxy Nexus only has a single internal partition. Other Ice Cream Sandwich phones in the future are likely to follow suit. ..
Lengthy discussion, and possible udev rules to fix this issue, in this forum:
OpenSuse.org > Cannot connect Samsung Galaxy S3 (Android 4) via USB cable
That's because it needs a udev rule
Can you plug the device in and then run the command dmesg, then post
the output for your device (in code tags), which should be the last
~10 entries. I can then add a udev rule to my package and update for
Once you have the updated package, you need to mount like;
jmtpfs -o allow_other ~/galaxy
To unmount use;
fusermount -u ~/galaxy
There is a man page, use man jmtpfs
A better explanation and suggested configuration (Nov 2011), so may be slightly outdated.
Ice Cream Sandwich explained: MTP - what is it, why use it, and how to set it up
MTP (Media Transfer Protocol) first showed up as default on Android devices with Honeycomb. It's a bit of a change from the normal USB Mass Storage (UMS) file transfer that we're used to, where you plug in your phone, hit "USB mode" and start moving files. And because it's become the standard in Ice Cream Sandwich on the Galaxy Nexus, it's time to have a look at it. Hit the break where we see what it is, why we're using it, and how to set it up on your computer for easy file transfer.
On a Linux install, things aren't quite as easy. On the plus side you have a bit of control how things are mounted, but there's no one click solution. Don't be discouraged, you can have MTP set up and running in no time with a bit of terminal command fun. Here's a walkthrough for using the Galaxy Nexus with Ubuntu:
Set up a UDEV rule via the terminal by opening the rules file ..
Will test this soon myself ..