Peter Gordon wrote:
How do you make that happen as the devices are autodetected? I'd much
prefer to have things identified by controller/drive/lun where applicable
than to have everything jump around when a new device appears and happens
to be detected first.
This is the great benefit of udev: dynamic device naming. It can track (via
sysfs querying) the actual make/model/SN of the device, and assign those to
specific device nodes (using symlink magic). For example, of you have a USB
memory stick made my FooBar Memory Company, it might register as sda or sdb
or anything else depending on when you plug it in, but udev can take that
item information, and automagically maintain an appropriate /dev/memstick
symlink which points to the appropriate device node.
Backwards compatibility sometimes means keeping support for things which,
while not inherently broken, prevent further beneficials workings of the
software in question.
The scenario I want to handle is being able to take some arbitrary,
probably used,
scsi disk, plug it into a working system, and know where to find it. It
may (in
fact it's pretty likely) that this disk is a dd image clone of another
drive already
in the system and all of the drives are likely to be the same
make/model. I know
from the SCA hot-swap slot or the cable/drive select where all the
drives are. I
don't want the system to guess about it or confuse one with the other.
And I
especially don't want it to move all the other drives around.
In other words they didn't care how much of how many people's time they
wasted. Just so they could make names that sounded cute to them. This
sort of user-hostility can only help Windows/OSX's market share.
They didn't care because in nearly every case, this is taken care of by
the respective downstream packagers per distribution. If you maintain your
own software without the aide of any such packaging, then it becomes your
responsibility to also take care of this new change.
Agreed - programmers should be allowed to make wild and crazy changes,
but nothing
should be included in a distribution knowing that it will break anything
currently
working unless you don't care about existing users - or there is no
other way to do it.
--
Les Mikesell
lesmikesell@xxxxxxxxx