Hello

I am facing a problem in one IBM server with RHEL AS3-U8. During installation it asked for boot parameters and the default valued shown is hdc=ide-scsi. In grub.conf this value has been registered.
kernel /boot/vmlinuz-2.4.21-37.ELsmp ro root=LABEL=/ hdc=ide-scsi

when I try to mount cd rom it throws an error like the following.

[root@myself root]# mount /mnt/cdrom/
mount: wrong fs type, bad option, bad superblock on /dev/cdrom,
or too many mounted file systems
(could this be the IDE device where you in fact use
ide-scsi so that sr0 or sda or so is needed?)

what could be this issue.

what is this parameter hdc=ide-scsi. I guess it is emulation of cd rom drive to scsi. Could some one give more details into that. What all modules are involved in it and how do we debug this issue.

If I remove the parameter hdc=ide-scsi from grub.conf file, I can mount dvd.

every thing works fine with AS3 U6. I mean I am able to mount dvd in AS3 U6, even though this parameter is set.

machine model:
Vendor: IBM
Version: IBM BIOS Version 1.36-[PAE136AUS-1.36]-
Release Date: 07/10/2006
Product Name: IBM eServer 206m -[8485PBT]-





Thanks
B

If stuff works fine with that ide-scsi thing removed, just go with it

Virtually ALL CD/DVD drives use the basic SCSI command set at some level, whether they are ATAPI drives or whatever, and as such, the drivers for ATAPI devices also natively are communicating using the SCSI basic commands. Unless you are actually using a specifically SCSI, NON-ATAPI device (which would probably be pretty old or very obscure) I think you can do without the option being in GRUB.

I am far from an 'experienced' user yet, but this is the way I understand it from reading the man pages for lilo, fstab, mount, lilo.conf, as well as some recent experience with my own CD/ROM device.
Perhaps between A6 and A8 there was a change to the modules? I can't really answer that with much conviction, because I just don't know.

You *might* try changing the option to 'hdc=ide-cdrom' and see if there is any difference.
I hope I have understood the problem, and at least shed a glimmer of light for you. If not, then hopefully one of the experts will have more accurate advice!
Best of luck..

Hi

Thanks for the reply. I think I got the problem. W
the background of the problem is that, when I install AS3 U6. things works fine - with hdc=ide-scsi in grub.conf file. where as when I install AS3 U8, it fails.

I found got to know that scsi emulation uses /dev/scd0 for cdrom. In case of U6 /dev/cdrom is pointing to /dev/scd0 where as in case of U8 it is pointing to /dev/hdc. this is where it failed. I changed the link to point to /dev/scd0 and things works fine.

devices start with s will generally used for scsi devices it seems. and for cdrom it is scd. first partition in scd drive will be scd0.

Even I am not very much thorough about the concepts to talk authentically. But things works well. !!! which is more important at this point time for me !!!!

-B

Hey that's great! Glad you got it sorted out and yes you are correct that *generally* the device names are indicative of their nature, ie. s for scsi, same as hd for hard disk.
Take care