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Re: How to minimize /dev (using udev)?



Marty wrote:
Hugo Vanwoerkom wrote:

But none of the posters showed proof that with/without udev actually
makes a *difference* that makes the system run *better*, other than
the number of devices. So what?


I could be wrong, but I thought the idea behind udev was that you don't
have to manually create your devices.  Reducing the number of device
entries is but a side effect, something that you would expect if it's
working properly.

Another important point is that udev can make sure that a given device
always gets the same identifier, no matter what other devices were
plugged in before it. (Otherwise it's "first come, first served".) Let's
say you wrote a nice script to make backups of your important data on a
USB harddrive. If you happen to have connected a camera before you
plugged in the harddrive, your script might try to save your data on
the camera instead. With udev you can assign device names based on
serial numbers, MAC addresses and other unique properties. Your script
will then reliably save the data when using an identifier such as
"/dev/backupdrive". (You can assign whatever device name you like, as
long as it does not exist already.) udev furthermore works together
nicely with other packages to offer convenient ways to automount
devices, have icons appear on the desktop automatically, etc.

I also thought it was required by the hotplug package, especially for
removable devices, but now I notice that few packages depend on it, and
no packages on my Sarge systems depend on it.  Maybe that will change in
the future.

udev replaces hotplug. On Etch and Sid you can use either one at the
moment (as far as I can tell), but I think the plan is that udev will
make hotplug obsolete before Etch becomes stable.

Regards,
          Florian



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