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ke
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 Posted: Wed Oct 29, 2008 2:44 pm Post subject: weird cdrom problem |
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After I installed linux on my notebook(dual-boot with windows xp), the
cdrom drive can not be found in both os's.
The weird thing is that I can still boot with a cd (for example, linux
rescue cd). But after installation /dev/cdrom does not exist, and
there is no cdrom entry in fstab or mtab.
I had an accidental power-off during setup (battery used up). I guess
the notebook firmware somehow went wrong?
* what is the possible cause?
* how can I check the existence of cdrom drive in linux?
* how can I know, when booting from cd (linux rescue mode), which
device it is using? How can I mount cd under linux rescue mode? |
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The Natural Philosopher
Guest
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| Posted: Wed Oct 29, 2008 9:03 pm Post subject: Re: weird cdrom problem |
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ke wrote:
| Quote: | After I installed linux on my notebook(dual-boot with windows xp), the
cdrom drive can not be found in both os's.
The weird thing is that I can still boot with a cd (for example, linux
rescue cd). But after installation /dev/cdrom does not exist, and
there is no cdrom entry in fstab or mtab.
Ah. |
So its in the bios, but the drivers have been disabled..
I'd gop and check bios settings anyway, as its weird it doesn't show up
in widows.
| Quote: | I had an accidental power-off during setup (battery used up). I guess
the notebook firmware somehow went wrong?
* what is the possible cause?
* how can I check the existence of cdrom drive in linux?
* how can I know, when booting from cd (linux rescue mode), which
device it is using? How can I mount cd under linux rescue mode?
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Bill Marcum
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| Posted: Thu Oct 30, 2008 4:38 am Post subject: Re: weird cdrom problem |
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On 2008-10-29, ke <ke_hang@yahoo.com> wrote:
| Quote: | After I installed linux on my notebook(dual-boot with windows xp), the
cdrom drive can not be found in both os's.
Which linux distro? |
| Quote: | The weird thing is that I can still boot with a cd (for example, linux
rescue cd). But after installation /dev/cdrom does not exist, and
there is no cdrom entry in fstab or mtab.
I had an accidental power-off during setup (battery used up). I guess
the notebook firmware somehow went wrong?
* what is the possible cause?
* how can I check the existence of cdrom drive in linux?
* how can I know, when booting from cd (linux rescue mode), which
device it is using? How can I mount cd under linux rescue mode?
ls /dev/hd* /dev/sd* (if it's an older distro, it will list every possible |
IDE or SCSI drive; a newer distro will only show the drives that are
currently detected).
--
They can't stop us... we're on a mission from God!
-- The Blues Brothers |
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ke
Guest
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| Posted: Thu Oct 30, 2008 3:21 pm Post subject: Re: weird cdrom problem |
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Problem solved.
I installed an older version of linux, Redhat 7.2; and used lilo
instead of grub as the boot loader. A boot parameter of lilo
hdd=ide-scsi
made the cd drive visible to both windows and linux. |
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Michael Black
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| Posted: Thu Oct 30, 2008 9:05 pm Post subject: Re: weird cdrom problem |
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On Thu, 30 Oct 2008, ke wrote:
| Quote: | Problem solved.
I installed an older version of linux, Redhat 7.2; and used lilo
instead of grub as the boot loader. A boot parameter of lilo
hdd=ide-scsi
made the cd drive visible to both windows and linux.
First, that's an old distribution, and more recent kernels don't |
require it.
But, it was never needed for reading CDs. The scsi emulation was
needed only for writing to CDs.
Michael |
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Nico Kadel-Garcia
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| Posted: Fri Oct 31, 2008 11:30 pm Post subject: Re: weird cdrom problem |
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ke wrote:
| Quote: | Problem solved.
I installed an older version of linux, Redhat 7.2; and used lilo
instead of grub as the boot loader. A boot parameter of lilo
hdd=ide-scsi
made the cd drive visible to both windows and linux.
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OK, it may help you to know some of the history on that. The author of
cdrecord, understandably, wrote it for SCSI devices for various technical
reasons. But most CD drives are IDE, so some smart aleck wrote a kernel module
to provide a SCSI like interface. This is not necessary at all for normal
reading, only noormal writing, at least from my reading of that old widget.
The drive would show up as both IDE and SCSI when doing this.
But he wrote, or included, what are basically *BAD DIRECTIONS* to do it. This
does not need to be, and should not be, in the LILO, or boot loader, it can be
manually or automatically loaded after boot time, much as network drivers can
be so loaded. This prevents all sorts of interesting conflicts.
More contemporary versoins of the Linux kernel have built-in drivers to handle
IDE, ATA, or PATA drives correctly, and the latest published versions of
RedHat all have updated versions of cdrecord and DVD writing tools which
support writing to IDE or PATA devices.
(Note: SATA drives look like SCSI to Linux users.) |
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ke
Guest
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| Posted: Sat Nov 01, 2008 1:53 am Post subject: Re: weird cdrom problem |
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| Quote: | But, it was never needed for reading CDs. The scsi emulation was
needed only for writing to CDs.
Michael
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You're right.
I checked lilo.conf. It turns out that the scsi parameter is not set
for windows.
I guess the grub boot loader of the previous linux installation
(Ubuntu 8.04) was corrupted.
Ke |
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