Automounting - How does it work?

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#1

Hi there,

I am trying to modify the auto mounting behavior of OpenSuse 11.2 (with a view of modifying the same in SLES 11.1).

Put simply, /etc/auto.master has a single active entry:

+auto.master

With this, any removable media (USB sticks, remvable disks, DVDs, etc) are mounted as their own volume name under /media.

However, I would like to map a RDX removable disk drive under /media/rdx - consistently - regardless of the volume name.

So I have added

/media /etc/auto.misc

to the bottom of auto.master and added

rdx -fstype=auto,rw,sync /dev/sdb1

  • to the /etc/auto.misc file.

This works - it mounts the rdx disk reliably.

However, nothing else now automounts.

So, my question is, is the “out-of-box” automounting feature controlled by autofs?

If so, where does the directive +auto.master point to? (ie what script can I look at that explains what follows?)

If not, what controls it (is it udev?), and where do I look to further understand the process?

Thanks in advance- Patrick

#2

IMHO what is called “automounter” for years in Unix/Linux and is configured starting with /etc/auto.master (it mounts (NFS) partitions when one needs the data inside that partition) is completely different from what a lot of people here call automounting.

They mean the actions taken by HAL (replaced newly by, sorry forgot the name), on behalf of a desktop when USB storage devices are connected to a system. HAL mounts inside /media (hard coded). See also SDB:Basics of partitions, filesystems, mount points - openSUSE.

Or am I lost here?

#3

Hi Henk, thanks for the clarification - I will check out hal/udev.

There still must be some interplay between the auto.master and udev, because modifying auto.master in the manner I described seems to break the function meant to be performed by udev… I’ll get to the bottom of it though.

thanks again /patrick

#4

You are welcome.

There is a big difference between udev and the rest. the udevd sees that the special files in* /dev/* are created. These are directly related to (simulated) hardware. When it is about storage, the the special files in /dev/ can be used for a mount (regardless if this mounting is done through Hal or not). But you can also mount using other things then special files in* /dev*, think about an NFS mount using a <Host>:<directory> expression.

It is not exactly clear to me why configuring the automounter influences HAL (and that is one of the reasons I answered to this, being curious ;)). But it could be related to the fact that HAL does not handle special files that are allready in* /etc/fstab*. The idea behind it is imho that when there is an entry in* /etc/fstab* then the sysadmin allready claims he knows what should be done, thus there is no task for HAL.

EDIT: I forgot to give you a welcome here on the forums. Seeing now that you have two posts, the start of this thread must have been your first post. Welcome again and enjoy.

#5

The one thing I did notice from the autofs man page…

rdx -fstype=auto,rw,sync :/dev/sdb1

As to the rest well out of my depth.