Udev: Assign unique names to your devices: Difference between revisions

Latest revision as of 17:49, 17 October 2008

[udev] was born for this job. This is fun stuff! (I'm a sick geek.)

Make sure you've emerged [sys-fs/udev] and [sys-apps/baselayout].
Put [/etc/udev/rules.d/10-local.rules] under version control, you're going to put your rules there.

Make sure the kernel has the following enabled:

File systems --->
  Pseudo filesystems --->
    [*] /proc file system support
    [*] Virtual memory file system support (former shm fs)

Run [lsusb], plug your device in, run it again and compare. This will show you the bus+device+deviceid. For USB devices, you can use the Device ID as a unique identifier.
If needed, run [lsusb -D /proc/bus/usb/#bus#/#device#] to find out everything about your device.
If you still want more help, plug in your device while watching /var/log/messages to get the dev path, then use this to get more udev identifiers:
```
udevinfo -a -p `udevinfo -q path -n /dev/sda`
```
Write a rule using the selected identifier. Add it to [/etc/udev/rules.d/10-local.rules]. Here's one using a device with ID [090c:6000]:
```
BUS=="usb", SYSFS{idVendor}=="090c", SYSFS{idProduct}=="6000", NAME="sdhc_via_usb"
```

Tell udev to reload rules, and wait for it to finish:

udevadm control --reload_rules
udevadm trigger
udevadm settle

Remove and re-plugin your device. It should now show up at [/dev/your_name]!
If it's a drive, add a mount rule to [/etc/fstab] like this:
```
/dev/sdhc_via_usb /mnt/8gb_sdhc vfat
```
Now you can mount your device reliably, using the mount path, no matter where you plug in your device, or what order you plug it in.
```
mount /mnt/8gb_sdhc
```
Pretty cool, eh?

Next, we'll work on automounting your device when it is inserted...

@@ Line 21: / Line 21: @@
 udevadm settle</pre></li>
 	<li>Remove and re-plugin your device.  It should now show up at [/dev/your_name]!</li>
-	<li>If it's a drive, add a mount rule to [/etc/fstab] and mount it using the new dev path.  Pretty cool, eh?</li>
+	<li>If it's a drive, add a mount rule to [/etc/fstab] like this:
-	<li>Next, we'll work on firing off a script to automount and autorun when the device is inserted...</li>
+<pre>/dev/sdhc_via_usb /mnt/8gb_sdhc vfat</pre></li>
+	<li>Now you can mount your device reliably, using the mount path, no matter where you plug in your device, or what order you plug it in.
+<pre>mount /mnt/8gb_sdhc</pre>Pretty cool, eh?</li>
 </ol>
+Next, we'll work on [[Automatically mount and unmount your devices|automounting your device]] when it is inserted...