automatic mount any external drive under /media with read/write access to everyone

Question

Here is my issue:

My computer has 4 USB ports and is running Ubuntu 12.10. I receive different USBs every day, plug to my computer, read/write data to them, and then send them away.

What I want is to automatically mount any USB I plug into my computer. The first detected USB will go to /media/HDD1, the second will go to /media/HDD2 and so on. Or it would be great if USB plugged to port1 will go to /media/HDD1, USB plugged to port2 will go to /media/HDD2, and so on.

The path /media is not important but I would like the HDD1-4 directories in one place so that I can easily access them.

The USBs are normally ext2 but sometimes I get FAT32, NTFS USBs as well.

I also want USB to be mounted without logging in to Ubuntu as I often access /media/HDD.. from another Windows computer.

How can I do that? What change in udev rules, fstab should I make? Any suggestion is highly appreciated.

Solution 1

Well, here we can use the same trick that fstab uses for Optical media (aka CD's and DVD's):

/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto     0       0

The first column indicates the file system, I'm sure your USB's will have fixed values, so lets presume that everything after sda is a USB, and since you can only have 4 USB's at the same time, the list goes from sdb, sdc, sdd and sde.

$ ls /dev/sd*
/dev/sda   /dev/sdb   /dev/sdb3  /dev/sdb6  /dev/sdc  /dev/sdf
/dev/sda1  /dev/sdb1  /dev/sdb4  /dev/sdb7  /dev/sdd
/dev/sda2  /dev/sdb2  /dev/sdb5  /dev/sdb8  /dev/sde

_{(In my case I use a memory reader, so my USB drivers start from sdg but lets continue.)}

Now, we assume each USB have one and only one partition, so the lines we need, for our fstab, are:

/dev/sdb1
/dev/sdc1
/dev/sdd1
/dev/sde1

Then you said your mount points has to be fixed, so after you have created your directories, lets add them:

/dev/sdb1 /media/HDD1
/dev/sdc1 /media/HDD2
/dev/sdd1 /media/HDD3
/dev/sde1 /media/HDD4

Since you can have almost all type of file systems, lets use the auto so fstab guess the file type to use:

/dev/sdb1 /media/HDD1 auto
/dev/sdc1 /media/HDD2 auto
/dev/sdd1 /media/HDD3 auto
/dev/sde1 /media/HDD4 auto

Ok, now lets boil down to the options, which will be the very same for CD's with the plus of read/write permissions:

/dev/sdb1 /media/HDD1 auto rw,users,noauto,allow_other,umask=0
/dev/sdc1 /media/HDD2 auto rw,users,noauto,allow_other,umask=0
/dev/sde1 /media/HDD3 auto rw,users,noauto,allow_other,umask=0
/dev/sde1 /media/HDD4 auto rw,users,noauto,allow_other,umask=0

rw tells that we want read and write permission, users allows any user to mount a device, noauto prevents that the driver gets mounted automatically when mount -a is called, like it does at boot, preventing boot ERRORS and WARNINGS, allow_other allows other but the user that mounted the driver to have the same permissions, and umask=0 prevents the defaults umask from being applied.

Now the only 2 left fields are pretty much just about the dump order and fsck order, which could be in 0 both, leaving us with the final result:

/dev/sdb1 /media/HDD1 auto rw,user,noauto,allow_other 0 0
/dev/sdc1 /media/HDD2 auto rw,user,noauto,allow_other 0 0
/dev/sdd1 /media/HDD3 auto rw,user,noauto,allow_other 0 0
/dev/sde1 /media/HDD4 auto rw,user,noauto,allow_other 0 0

With this, each time that you plug a USB device it will being automagically mounted in the mount point without the intervention of the user. You should modify according to your necessities.

Solution 2

Here is the solution I found:

Firstly I install autofs on my linux PC:

sudo apt-get install autofs

It will create auto.master file under /etc/auto.master

Add the following line at the end of that file:

/media/mount /etc/auto.mount --timeout=10 --ghost

/media/mount is a directory where I want to mount all external drives into. /etc/auto.mount is the file to put in mounting rules. --timeout=10 means it will automatically unmount the drive after 10 sec of inactivity. --ghost means it still leaves a picture of content when it is unmounted. Change this line according to your needs.

Edit the /etc/auto.mount file and add the following lines:

disk1  -fstype=auto,sync  :/dev/sdc1
disk2  -fstype=auto,sync  :/dev/sdd1
disk3  -fstype=auto,sync  :/dev/sde1
disk4  -fstype=auto,sync  :/dev/sdf1
disk5  -fstype=auto,sync  :/dev/sdg1
disk6  -fstype=auto,sync  :/dev/sdh1
disk7  -fstype=auto,sync  :/dev/sdi1
disk8  -fstype=auto,sync  :/dev/sdj1
DVD    -fstype=iso9660,ro :/dev/sr0

For normal drives such as USB or eSATA set -fstype=auto,sync. I have 8 USB+eSATA ports so I declare 8 mount points here. My PC already has sda and sdb as local disks so I put sdc1 -> sdj1 for external devices. They are actually device nodes in /dev when you plug your drives in. An exception of mounting rule is DVD mounting as you see above.

When I insert any drives they will show up as disk1, disk2, ... under /media/mount directory, and will auto-unmount after 10 seconds. I don't need to touch my PC and can access it from somewhere else (such as Virtual machine)

Comments

[Kiwi]

thank Braiam. I'm not sure if changing fstab can automatically mount USBs without the need of reboot or using "mount" command. I found a simple solution of using autofs. Not only does it automount but also supports auto-unmount after pre-defined time of no action, which is very useful in my case

[Braiam]

No, it doesn't. As I said at the beginning, I was using the same trick fstab uses for CD/DVD that don't require the use of root nor mount nor restart.