diff --git a/Deconstructing_Linux_udev_Rules.rst b/Deconstructing_Linux_udev_Rules.rst index 1602864..fd745f3 100644 --- a/Deconstructing_Linux_udev_Rules.rst +++ b/Deconstructing_Linux_udev_Rules.rst @@ -18,31 +18,34 @@ Original ``Unix`` derivatives had a static tree of devices the system could support. This was encoded in the ``/dev`` file tree hierarchy. This was pretty inflexible in the face of devices being added- and -removed- from the system as it ran. For this reason, modern device +removed from the system as it ran. For this reason, modern device handling in ``Linux`` and most other ``Unix`` derivatives is *dynamic* - the content of ``/dev`` changes to reflect the actual state of the system as things get connected or disconnected. (Exactly how this is done is outside the purpose of this document, but if you -care, investigate the ``Linux /sys`` filesystem works.) +care, investigate how the ``Linux /sys`` filesystem works.) Our Example Problem =================== While the example below is "cooked", it is very much rooted in real -world ``udev`` application. We want to do the following things: +world ``udev`` applications. We want to do the following things: - - Make sure that a particular disk always shows up under the same - name under ``/dev`` no matter how many disks have been connected - before it. We do that by uniquely identifying a disk and then - creating a symbolic link to it that never changes. + - Identify a specific disk no matter what name it was assigned + name under ``/dev``. + + - Create a symbolic link to that disk so that - no matter + what it's name under ``/dev/`` might be at the moment - + the symbolic link is always the same. - Change the user and group ownership of that disk to something - other than the default of ``root:disk``. + other than the default (``root:disk``). - - Create a corresponding "raw" character device under ``/dev/raw``. - This is something you commonly see on database servers and - it's suffiently useful that's it's worth mentioning here. + - Create a corresponding "raw" character device under ``/dev/raw`` + associated with our disk above. This is something commonly + seen on database servers and it's suffiently useful that's it's + worth mentioning here. Where Do ``udev`` Rules Live? @@ -64,7 +67,7 @@ Document Revision Information ============================= -``$Id: Deconstructing_Linux_udev_Rules.rst,v 1.102 2013/10/31 21:45:08 tundra Exp $`` +``$Id: Deconstructing_Linux_udev_Rules.rst,v 1.103 2013/10/31 21:50:07 tundra Exp $`` You can find the latest version of this document at: