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Re: Linux is not about choice [was Re: Fedora too cutting edge?]

Arthur Pemberton wrote:
On Jan 11, 2008 2:30 PM, Les Mikesell <lesmikesell gmail com> wrote:
It doesn't seem as sensible as being able to plug into a known
controller position and get a known device name, particularly in the
scenario where the drives aren't hot-plug and you want to access a bunch
of new ones after a reboot and know which is which.

Frankly i like this idea, but I'm unsure of the practicality of it:

What is the highest level which is even aware of the physical location
of said device? I would imagine the BIOS knows, and maybe some really
low level kernel modules but anything above that?

udev is fully aware of the physical location, because it knows the communication bus addressing to the device itself (/dev/disk/by-path). What Les is asking for is a consistent guaranteed device node naming scheme, which makes good sense for machines with few devices (desktops, small servers) and less sense for larger systems. The facts are the older scheme wasn't guaranteed to be deterministic, it just seemed to be because the kernel would probe / name the devices in sequential order, and its no longer guaranteed to do that (that still doesn't mean anything is named randomly).

I suppose someone could have additional udev rules that would follow the older naming scheme at the same time as the new one... just doing the 'magic guesswork' to make sure things always got named in the predictable ordering.

Andrew Farris <lordmorgul gmail com> <ajfarris gmail com>
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No one now has, and no one will ever again get, the big picture. - Daniel Geer
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