Re: My CD and DVD are messed up
On Tue, 28 Jun 2011 20:32:28 +0200, lee wrote:
> Camaleón <noelamac@gmail.com> writes:
>
>> Your primary device (dvd?) should point to "/dev/cdrom0" and secondary
>> (cd-rom?) to "/dev/cdrom1".
>
> How does the system decide what the "primary device" and the "secondary
> device" are supposed to be?
That used to come from a BIOS setting.
- SATA port 0 comes before SATA port 1 and so on...
- IDE interface can be set to be detected before or after SATA...
- SCSI devices attached to the controller can be managed at first or
after SATA/IDE...
> It seems to me that, to the system, DVD drives look very much like CD
> drives: There's /dev/scd0 and /dev/scd1, for example. Either of the
> two can be a CD or a DVD drive, IIRC.
Yep, priority is deciced based only in a controller/port setting. *But*
with today udev automatisms, I wouldn't put my hand in the fire for that
:-)
> Unlike hard disks, these devices aren't detected by UUID, are they?
Let's see:
sm01@stt008:~$ ls -l /dev/disk/by-uuid/*
lrwxrwxrwx 1 root root 10 jun 28 07:56 /dev/disk/by-uuid/c6454fe5-20a5-4a58-bbdd-2f2c52dd5ca2 -> ../../sda3
lrwxrwxrwx 1 root root 10 jun 28 07:56 /dev/disk/by-uuid/cabbc008-f461-4691-b799-36fe39f39c68 -> ../../sdb1
lrwxrwxrwx 1 root root 10 jun 28 07:56 /dev/disk/by-uuid/ff87e2f7-0a9c-4cb8-bedb-eac6b479ef59 -> ../../sda2
My DVD unit is not there.
Indeed, is not under any "/dev/disk/*" node. Udev creates a symbolic link
/dev/sdc* which points to /dev/sr*.
> Perhaps the OP can figure out which devices he has, which is which, make
> appropriate entries in /etc/fstab and hope that the order of devices
> doesn't change?
Yep, or use udev rules:
CD/DVD drives
http://reactivated.net/writing_udev_rules.html#example-cdrom
:-)
Greetings,
--
Camaleón
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