Annoying udev problem with 2 DVD-ROM drives [SOLVED]

evoweiss · Last edited by evoweiss on Sun Feb 04, 2007 8:43 pm; edited 3 times in total

Hi all,

For some time udev has been messed up with respect to handling two dvd rom drives. Usually it's ok, but sometimes it misassigns names so that the dvd drive that was assigned 0 is now assigned 1 and vice versa. I know that the original device names (hdc and hdd) are ok and still correspond to the correct drives, but when the devices are made via udev, it can be screwed up sometime. Also, I just managed to temporarily fix the problem by typing in udevstart from root.

Anybody have an idea of how to permanently fix this annoyance?

Best,

Alex

NeddySeagoon · Posted: Sun Nov 26, 2006 10:05 pm Post subject:

evoweiss,

Use /dev/hdc and /dev/hdd in /etc/fstab or follow this guide to write some udev rules to fix the names based on the serial numbers or something unique to each drive.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

evoweiss · Posted: Sun Nov 26, 2006 11:17 pm Post subject:

Hey NeddySeagoon,

Adding the following lines to /etc/udev/rules.d/50-udev.rules did the trick:

NeddySeagoon · Posted: Sun Nov 26, 2006 11:21 pm Post subject:

evoweiss,

Don't do that, etc-update will want to replace that file every time udev is updated.
Make a new file that starts with a number less than 50, otherwise any name you like. Rules files are run in order, starting with 00 and you want your rules to be applied before the defualt 50-udev.rules.

Put your CDROM rules in your new file, then you won't be disappointed when you run etc-update.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

evoweiss · Posted: Sun Nov 26, 2006 11:26 pm Post subject:

Hi again NeddySeagoon,

Done!

Alex

evoweiss · Posted: Sun Dec 03, 2006 4:15 pm Post subject:

Hi again all,

Unfortunately, that didn't solve the problem as a reboot caused the drives to be misassigned again! However, I found out that typing in udevstart fixes the problem. So, in short, what the hell am I doing wrong? To fix this annoying problem with the HDDs time being out of sync I hadded a file .critical to the /etc/runlevels/boot/ directory. It contains the following:

chewbar · n00b Joined: 03 Jan 2007 Posts: 2

Hi.

I have exactly the same situation with two dvd drives. My new rules work fine when if I run udevstart but I want the devices to be created at boot time.

Does anyone know whether this is the correct behaviour or not? Surely udev should be started at boot..

Thanks.

gary · Posted: Fri Jan 05, 2007 3:23 am Post subject: Me too!

Same problem here.

I have a SCSI cdrw and an IDE cdrom.

UDEV now wants to link cdrom, cdrom1, cdrw, and cdrw1 all to sr0, which is my cdrw. It works like a champ, but my cdrom is not accessible.

Running udevstart reassigns cdrom and cdrom1 to hdb, which is correct. It also creates cdrom3, cdrw2 and cdrw3, which did not previously exist.

Strange.

Perhaps we do not have UDEV starting when or how it should at boot? How could we check?

PaulBredbury · Watchman Joined: 14 Jul 2005 Posts: 7310

I'd just add custom rules to 10-local.rules, to force udev to use the right names the first time.

evoweiss · Posted: Sat Jan 06, 2007 6:11 pm Post subject: Re: Me too!

PaulBredbury · Watchman Joined: 14 Jul 2005 Posts: 7310

man udev mentions debug in /etc/udev/udev.conf

holycow · n00b Joined: 04 Jul 2005 Posts: 29

I use 80-local.rules to tell udev to set the proper symlinks. This lets you override udev rules.

evoweiss · Posted: Wed Jan 10, 2007 10:55 pm Post subject:

PaulBredbury · Watchman Joined: 14 Jul 2005 Posts: 7310

evoweiss · Posted: Wed Jan 10, 2007 11:09 pm Post subject:

Hi,

I've got a logger and here's what I see in my everything log file.

PaulBredbury · Watchman Joined: 14 Jul 2005 Posts: 7310

evoweiss · Posted: Wed Jan 10, 2007 11:24 pm Post subject:

Bump...

evoweiss · Posted: Mon Jan 29, 2007 8:26 pm Post subject:

Re-bump...

branchcut · Posted: Wed Jan 31, 2007 1:34 am Post subject:

I'm having issues in this area as well. I have a DVD-ROM drive for hdc and a DVD Writer for hdd. Unfortunately, the symlinks look like this:

cdrom -> hdd
cdrom1 -> hdd

Any ideas?

Desmond
_________________
Blessed Are They Who Go Around In Circles,
For They Shall Be Known As Wheels

evoweiss · Posted: Sun Feb 04, 2007 8:43 pm Post subject:

Hi all,

Upgrading to udev-104-r8 fixed it for me. If it seems to work for everybody else, let's mark this as solved.

Best,

Alex