GNU/Linux Desktop Survival Guide by Graham Williams
Desktop Survival Project Home Preface Advocacy History Distributions Installation Basic Survival Wajig Audio AbiWord APM Backup Bash Booting Cameras CD Chinese ChRoot Clock Commercial Conference Management Configuration CRON CVS Databases DIA Directories Disks Documentation DVD Email Eye of Gnome Evolution File Systems Firewalls Floppy Disks Fonts Ghemical GIMP Glade Gnome GnuCash Gnumeric GQView Graphics Groups HTML Editors ImageMagick Initialisations on Booting Java KDE Kernels Keyboard Konqueror KVM Switch LaTeX Log System Login Magellan Mathematics Memory Modems Mounting Devices MS/Windows Music MySQL Nautilus Networks NFS NT File System OpenOffice.org Oracle Packages Partitions Passwords PDF Photos PPP Presentations Printing Python R Remote Desktops Rsync Samba Scanning Science Security SH File System Sketch Spell SPlus Spruce SSH SUDO Subversion Swap Themes USB Video Virtualization Web Word X XML Sample Installations Troubleshooting Index

Using UDEV

Debian Packages: udev hotplug

A problem that plagued earlier versions of the GNU/Linux kernel was that each time a USB device (and other devices) was connected a different mount point would be assigned. This issue was addressed in the 2.6 kernels using udev with hotplug. With udev, naming rules (e.g., in /etc/udev/rules.d/local.rules) are used to provide stable names for use in /etc/fstab. Udev uses information exported by the kernel drivers to the sysfs filesystem (usually mounted on /sys) to identify specific devices and to then associate them with specific names in /dev.

The key to using udev is with the rules that are defined to identify and distinguish the different USB devices that may be connected. A tutorial for writing udev rules is available from http://www.reactivated.net/udevrules.php.

The first step is to identify the USB device in some way. The udevinfo command can be used to identify a device path, which can then be used to identify information about the device on that path. For example, to identify a specific Flash Memory device which is recognised in GNU/Linux as a SCSI device, connect the device and run the command:

  $ udevinfo -a -p $(udevinfo -q path -n /dev/sdc)

The /dev/sdc path here is whatever the dmesg command identifies. Select some identifying piece of information, like the product identifier (the line that starts with SYSFS{product}=), and add that to /etc/udev/rules.d/local.rules (each rule must be on a single line).

Subsections

• Flash Memory
• Camera
• iPod
• Card Reader
• MP3 Player
  • iRiver H340
  • iRiver ifp796
  
  
• Ethernet Cards
• Examples