I recently interchanged the ide cables leading to the hd and dvd drive. I booted with the cables in the wrong slots and later realized that they should be switched around.

Now, my ide hd (hda1) mounts but my dvd drive (formerly hdc), doesn't. How do I manually set the mount point for my dvd drive back to /dev/hdc; its default mount point.


$cat /var/log/messages grep hdc (incorrect, now fixed)
Dec 30 01:38:24 agent kernel: hdc: QUANTUM FIREBALLlct15 30, ATA DISK drive
Dec 30 01:38:24 agent kernel: hdc: attached ide-disk driver.
Dec 30 01:38:24 agent kernel: hdc: 58633344 sectors (30020 MB) w/418KiB Cache, CHS=58168/16/63, UDMA(66)



When the mount point for the dvd drive was hda, the boot output looked as it should...

Dec 30 01:38:24 agent kernel: hda: HL-DT-ST DVDRAM GSA-4163B, ATAPI CD/DVD-ROM drive
Dec 30 01:38:24 agent kernel: hda: attached ide-cdrom driver.
Dec 30 01:38:24 agent kernel: hda: ATAPI 63X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache, UDMA(33)

Now, it can't spec it or anything. It knows something's there, but that's it.

Dec 30 01:51:54 agent kernel: ide0: BM-DMA at 0x1800-0x1807, BIOS settings: hdaMA, hdbioDec 30 01:51:54 agent kernel: ide0 at 0x1f0-0x1f7,0x3f6 on irq 14


I apologize if the explanation is confusing. I tried to make it as clear as possible.


I hope the solution isn't blatantly obvious. It certainly isn't to me.

Thanks

First check the BIOS to make sure it recognises the DVD. The cable may have gone bad when being swapped. If the BIOS recognises the DVD then you just need to check /etc/fstab to see where the cdrom is being mounted (usually /mnt/cdrom) and make sure it is mounting /dev/hdc.

If your kernel is 2.4 then of course you need scsi-emulation for cdburner, however if the kernel is 2.6 you don't.

Try this ls -l /dev/hdc and make sure there is r/w permissions for the device.

You can also try putting a bootable cd in the drive to see if it works. As a last resort if you have Windows installed you could boot into windows and see if the drive works in windows, to eliminate any cable/hardware issues.

I'll have to check the BIOS at some point.

I commented out /dev/hdc in fstab because I started using /dev/cdrom and I also read in XCDRoast's FAQ that 'options ide-cd ignore='hdc hdd'' must exist in /etc/modules.conf. It's always worked in the past, though, even without hdc in fstab. Maybe I should uncomment it for the time being and comment it out again later--assuming it's even necessary.

The filesystem is /dev/cdrom(dvd) and the mount point is /mnt/cdrom(dvd). I spent a lot of time getting my dvd drive to work with the stupendous help of a user here at LQ.

I actually switched the cables around a great many times before this, so I doubt the cable has gone bad. Also, I just recently burned MEPIS and Knoppix to cd's in Windows.

The funny thing regarding scsi-emulation is that I have two separate grub entries--one with '/vmlinuz-2.4.27-2-386 root=/dev/hde5 ro' and a second (scsi-emulation) with '/vmlinuz-2.4.27-2-386 root=/dev/hde5 hdc=scsi hdd=scsi ro single'. I never remember manually selecting the scsi-emulation one every time I booted, but it is possible I selected it at one point and it made use of savedefault.

/dev/hdc has rw permissions.

Bootable cd's worked last I checked but I don't remember trying since I've run into this problem, although I'm nearly certain it will work without fault.


Thanks

*&%#. It looks like my ide cable is dead. I can't believe it; it was just working and now it has gone bad. MEPIS won't boot anymore and the drive doesn't appear in Windows's Device Manager. I wonder why it didn't go dead the dozen other times I swapped them. Well, I guess I'll just have to replace the cable... shouldn't be difficult.

That was a great theory.
Thanks


edit: I also checked barebones BIOS and all it says for the dvd drive is 'atapi cdrom drive', but it apparently detected it.

Sometimes you can take a pair of pliers and squeeze the top and bottom of the connector and fix a bad ide cable. If the bios detects the drive then the cable isn't totally bad. Maybe it just has 1 or 2 loose connections.

Oops, I already bought a new ide cable. They sure are a lot beefier, roughly 7 years later. Really nice.

Everything is running smoothly now.

I appreciate your help.

Well, you can still try to fix the old one and then you have a backup.

HTH