I have CDRW and DVDROM drives, hdc and hdd, but for the past few weeks /dev/hdc doesn't exist...hdc exists and burns CDs fine when I boot from Knoppix, but there's no such file in my permament OS ubuntu 4.1 warty, kernel 2.6.8. I have the option hdc=ide-scsi to grub's menu.lst. The only thing I can think of that changed recently is that I connected a 2nd hard drive as slave for a while but have since disconnected it and BIOS still reports my main hd, CDRW and DVDROM drives correctly.
OK, so running modeprobe ide_scsi then lsmod again confirms that I have ide_scsi and scsi_mod loaded...but I presume this needs to happen at boot for my cdrw drive to be recognised...? how do I set this up so it's loaded everytime?
Thanks for your help,
mrBen
02-17-2005, 10:46 AM
Well - first check that everything is working..... try and burn a CD, stuff like that ;)
you should be able to add it to the file /etc/modules to get it to load at bootup.
jaybee99
02-17-2005, 04:38 PM
/dev/hdc still doesn't exist after running modprobe ide_scsi and if I open xcdroast setup and scan for devices it finds /dev/hdd but not hdc...:(
blackbelt_jones
02-17-2005, 09:57 PM
Did you know that "Ubuntu" is an ancient African word meaning "overrated"?
;)
Sorry... that wasn't very Ubuntu of me.
bwkaz
02-17-2005, 11:19 PM
Originally posted by mrBen
IIRC 2.6 kernel doesn't require the drive to be defined as ide-scsi That is true.
although you will need the ide_scsi module That is not. ;) SCSI emulation over IDE is broken in 2.6, and that's all that ide-scsi does.
There are some other threads that may be helpful, too, if you search for "cdrecord" in the hardware section.
You will need an hdc file, but if you boot without "hdc=ide-scsi", and don't load the ide-scsi module, it should be created for you.
I don't have a hdc file though...removed hdc=ide-scsi and ide-scsi is definitely not loaded, goign on lsmod...:( I have also tried going back to my previous kernel 2.6.8.1-3 (it just occurred to me that I upgraded a couple of weeks ago through synaptic, maybe at same time cd cdrive disappeared...last time I'll be doing that)
bwkaz
02-18-2005, 07:52 PM
Well, OK, if it doesn't show up by default, you can do a:
mknod /dev/hdc b 22 0
as root to create it. You will probably also want to:
chown root:disk /dev/hdc
chmod 0660 /dev/hdc
to ensure that users who are not either root, or members of the "disk" group, can't access the raw device file.
If the device disappears after reboot, then something strange is going on... ;)
jaybee99
02-19-2005, 01:39 PM
Thx bwkaz, I used mknod as you suggest, cdrecord still can't see the device and after rebooting, it's gone! If other OS's couldn't see it and use it, I'd presume the device was dead, but they can.
why is hdc ignored? This seems like it must be something to do with the device, cos it's also bust in fedora core2 which is on another partition and it was previously working fine in both, so how come it works only in knoppix :confused:
bwkaz
02-19-2005, 10:24 PM
Originally posted by jaybee99
cdrecord still can't see the device Could you perhaps define "can't see", please? What are you telling it to do, and what does it say?
If you built ide-cd as a module, are you passing any parameters to it (through /etc/modules.conf) when it loads? If you didn't build it as a module, then what's in the kernel's command line (/proc/cmdline)?
jaybee99
02-20-2005, 05:34 AM
Originally posted by bwkaz
Could you perhaps define "can't see", please? What are you telling it to do, and what does it say?
If you built ide-cd as a module, are you passing any parameters to it (through /etc/modules.conf) when it loads? If you didn't build it as a module, then what's in the kernel's command line (/proc/cmdline)?
if I use mknod to create /dev/hdc then I can at least stat it. If I then use cdrecord
cdrecord: No such device or address. Cannot open '/dev/hdc'. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are root.
and cdrecord -scanbus produces
cdrecord: No such file or directory. Cannot open '/dev/pg*'. Cannot open SCSI driver.
The kernel's command line is
root=/dev/hda5 ro quiet splash
bwkaz
02-20-2005, 03:16 PM
Originally posted by jaybee99
cdrecord: No such device or address. Cannot open '/dev/hdc'. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure you are root. This error comes up (the part in bold, anyway) when the device file exists, but no kernel driver has said "here are the functions to call to handle requests on this block-major/block-minor combination".
Basically, either you don't have an hdc device in your system, or your IDE CDROM driver isn't handling that device (which usually happens because it's been told to ignore it). hdc is the secondary master; are you sure your CD-ROM is jumpered as a master? Is it connected to the secondary IDE channel? What's in /etc/modprobe.conf?
and cdrecord -scanbus produces
cdrecord: No such file or directory. Cannot open '/dev/pg*'. Cannot open SCSI driver. What about cdrecord dev=ATA: -scanbus? Normal -scanbus tries to use the original SCSI driver, and only works for CD writers on a true SCSI bus. dev=ATA: tells cdrecord to use the kernel's SG_IO interface over the /dev/hdX IDE device file (this is actually the same interface as the SCSI driver uses, it's just sent over a different device file).
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