Re: crc error when booting

[Tim Hurman <kano-tlug@example.com>]

Ok, installing from CDROM, here are some things to check:

One thing to try is reset the BIOS to the factory values. Most BIOSes are
able to force the clock on the DRAM to a series of values. If you have
slow memory and are clocking it too fast or fast refresh memory that isn't
being refreshed enough, it can cause these sorts of problems. Under
windows they just appear as a system crash. Also have you tried the
bootdisks?, on the Slackware CDROM, there are two disks you need, bare.i
and color.gz along with rawrite, a program to write them from under
windows. It may also be worth taking the cover off your pc and checking
the IDE cables for connectivity/damage. Also you could check that the DRAM
is seated properly. Also enable a full ram check in the BIOS (turn off
fastboot), this isnt the best ram checker, but it may show something up.

Tim.

On Wed, 5 Sep 2001, Stephen J. Turnbull wrote:

> >>>>> "Inc" == Inc Hatsuhiro <hatuhiro@example.com> writes:
>
>     Inc> 1) What is the meaning of "crc error"?
>
> The data read into memory is corrupted.  CRC means "cyclic redundancy
> check" (or something like that).  It is a simple check on data
> integrity, like a hash function or a parity bit.
>
>     Inc> 2) How can we get rid of this problem?
>
> Get good data into memory.  There are three conditions that must be
> satisfied:
>
>     1. The data on the CD must be correct.
>     2. The data must be copied from the CD to memory correctly.
>     3. Memory must receive it correctly.
>
>     Inc> I was supposing the bootable CD-ROM could boot Linux no
>     Inc> matter what file systems the HD had.
>
> Correct.
>
>     Inc> I tried booting old Slackware 3.6 Linux, but I got the same
>     Inc> message as above.
>
> This is bad.  Surely the kernels' data differ.  Also, the 3.6 is known
> to have worked at one time.  This means that most likely the data is
> correct on both CD-ROMs.
>
>   You can check this by using them to boot another machine; you should
>   be able to exit the install before changing anything on the hard drive.
>
> This means that the high probability is that your CD-ROM drive is
> broken, the controller is broken, or you have some bad memory.
>
>     Inc> Now, Linux system software but MS Windows doesn't work on my
>     Inc> computer, so I have no help, except for asking experts.
>
> Try reading the CD under Windows.  You should be able to at least use
> explorer on the filesystem.  If you get read errors under windows,
> too, then the CD-ROM drive is probably broken.  Hmm.  If you can find
> the kernel, do "type e:vmlinuz >nul:" (I think that should work) in a
> DOS box.  E: should be changed to whatever Windows thinks your CD-ROM
> is, and vmlinuz should be the name of the kernel.  Often its just "linux".
>
>     Inc> How do we troubleshoot it in that environment where no Linux
>     Inc> does work?
>
> With a rescue disk.  A "rescue disk" is just a boot floppy that comes
> with a known good root file system and some tools.  Often on a
> separate floppy.
>
> Linux _does_ work; the fact that boot disks get as far as "Kernel
> panic : VFS : Unable to mount root fs on 03:01" is _good_ news.  It's
> exactly what should happen.  "03:01" is the kernel's internal name for
> /dev/hda1, and you don't have a linux root partition there yet.  So it
> can't mount it.
>
> Do you have an old Linux installation on the disk (eg in /dev/hda2),
> or did that get reformatted/overwritten by the Windows install?
>
> If not and you remember which partition (assume /dev/hda2 for
> example), when the boot floppy types "boot:" you type
>
> linux root=/dev/hda2
>
> and you win.  Probably.