I’m using Ubuntu 8.10 64-bit, Intrepid Ibex, but these instructions should work for users of other distros (such as Linux Mint, Fedora, Sabayon, etc) as well.

This morning I needed to pull some images off of my camera’s SD card using my Dell Studio 17′s built-in card reader. I plugged the card in, got sidetracked for a few minutes, and then realized that I couldn’t find a mount point for my card.

Usually when I plug in the card, it is automatically identified and mounted. Then Nautilus would show a listing in the left-hand pane for the card allowing me easy access to the contents. However, that didn’t happen today.

I thought about rebooting in order to see if it was just a fluke, but I didn’t want to save all my projects, close out all my applications, reboot, and load everything back up. So, I thought I’d see about mounting the device manually. Fortunately, it wasn’t difficult at all.

Hardware Compatibility

I’m running a Dell Studio 1735 laptop. The exact card adapter that I’m using is a Ricoh R5C822. If you are not using the same adapter on the same computer, the instructions could vary greatly since the hardware configuration will be different.

To verify that you are using the same adapter, run the following command in Terminal (Applications > Accessories > Terminal):

lspci|grep R5C822

You should get output similar to the following if you have the same adapter:

03:01.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 22)

Of course, trying the following instructions even if your system varies is still worth a try. If you successfully use the instructions on a different system/adapter, please leave a comment about your results.

Mounting the Device

Simply run the following two commands in Terminal to mount the card to a new mount point called /media/cardreader:

sudo mkdir /media/cardreader
sudo mount /dev/mmcblk0p1 /media/cardreader

This should result in /media/cardreader being filled with the contents of the inserted card and by a new mounted device called cardreader poping up on Nautilus.

When you are done with the card, close out all the applications that are referring to files or folders on the card. You can then unmount it and remove the unneeded mount point by running the following:

sudo umount /media/cardreader
sudo rmdir /media/cardreader

If you need, you could create a couple of shell scripts to run these commands quickly when you need access to the card reader.

Conclusion

I still have no idea why my card reader did not automatically mount when I plugged in the card. My hope is that this is a temporary problem and not a persistent issue. I’ll test more later on. If this is more than a temporary issue, I’ll find a solution and post it here.

For right now, the card reader worked as expected after a reboot. I popped the card into the reader, and the pop-up asked me what I’d like to do with the files.

I recently ran into an issue where a mounted SSHFS filesystem refused to unmount.

I tried to unmount it from inside Nautilus by right-clicking the mount and selecting Unmount, but this failed with an error message. The error told me that it couldn’t unmount the device and gave a reason of “mount disagrees with the fstab”.

I then edited the fstab (sudo vi /etc/fstab) and commented out the entry for the device. I tried to unmount in Nautilus again, but this time it told me that I couldn’t unmount the device because I wasn’t root and the device was not listed in fstab. I then uncommented the previously commented line and saved the file again.

Time to get dirty. I ran “sudo umount /mnt/share” to try to force it, but this failed with a new error message:

umount: /mnt/share: device is busy.
        (In some cases useful info about processes that use
        the device is found by lsof(8) or fuser(1))

This was getting personal now as the previous messages said nothing about the device being in use. I closed out every application and tried again. Same error message.

I followed the instructions and ran “man lsof” followed by “man fuser” to find out more about those recommended commands. fuser was the winner.

fuser allows you to find out detailed information about processes that are using specific files or sockets. In addition to getting information, it allows you to kill processes accessing the file or socket. This was exactly what I was looking for.

After reading up on the fuser syntax, I ran the following:

sudo fuser -km /mnt/share

This command basically translates into “find every process that is accessing the /mnt/share mount point and kill it”. Since I was unsure of the ownership of the processes that would be killed, I ran it with sudo to make sure that any processes could be killed.

The command returned “/mnt/share/: 9004c” which I believe indicates that a process was killed.

Again, I ran:

sudo umount /mnt/share

This command cheerily replied with nothing, which is a good sign as it means that the umount command succeeded.

Finally, the mount is unmounted. Now if only I could remember what I was trying to do when this problem happened…