Assigning hardware paths

joopndufus · 07-26-2005, 09:05 PM

Hello,

I'm wondering if it's possible to assign a path to a certain piece of hardware that is plugged into my system. Basically I would like something like /dev/ipod when my ipod gets plugged in. I have both an external SATA drive and an Apple iPod. Depending on the order of when they are plugged in, they either are assigned to /dev/sda or /dev/sdb. As you can imagine, this greatly interferes with my scripts and my /etc/fstab file. So is there any way to specify how the device gets assigned it's /dev/ path?

mhen · 07-26-2005, 09:23 PM

are you using udev, devfs or a static /dev directory?

joopndufus · 07-26-2005, 09:29 PM

Code:

[jtkrol@joop ~]$ ps aux | grep dev
root       948  0.0  0.1   1640   560 ?        S<s  20:21   0:00 udevd

I think this means that I'm using udev, correct? Sorry for not posting more info. I'm running Fedora Core 4 on a Dell Inspiron 600m. Thank you!

mhen · 07-26-2005, 09:42 PM

I know that it is possible to do what you want with udev, it is one of the things that it was *designed* to do:

Quote:

Say that I have two printers - a HP laser printer and an Epson inkjet. When they are both plugged in and on, I have /dev/lp0 and /dev/lp1.
How do I know which node refers to which printer? There is no easy way. The first printer that got connected was assigned name "lp0", and the second "lp1". Plugging in my printers in a different order would swap the names here, and that would mess up my scripts that always expect my HP laser printer to be lp1.

However, if my HP laser printer got named lp_hp (as well as lpX) and my other printer got named lp_epson (as well as lpY), then my scripts could just refer to those names. udev magic can control this and ensure that these persistent names always point to the device that I intended.

Unfortunately, since I have never used udev, I don't know exactly how this is done, but you might find this useful (the source of the above quote):

http://www.reactivated.net/writing_udev_rules.html

joopndufus · 07-26-2005, 10:25 PM

So after I posted this, I stumbled upon this link for using an iPod with Gentoo:

http://gentoo-wiki.com/HOWTO_Using_a...oo_Linux#udevd

The section that I linked to has some information about creating a udev rule. In regards to my last post, does that mean I'm running udev? I'm assuming so, but I would like some confirmation!

mhen · 07-26-2005, 10:34 PM

since udevd is running, then yes, I would say that you are using udev.