From: Michele Andreoli (m.andreoli@tin.it)
Date: Thu Feb 15 2001 - 21:01:56 CET
On Thu, Feb 15, 2001 at 07:06:40PM +0100, Uwe Sonnenberg nicely wrote:
> Hi, a question from a mulinux starter.
> I have tried different 11rX versions to clone mulinux to HD on two
> different machines, equipped with Adaptec SCSI.
> The target is to boot and work without a floppy.
> Using floppy based mulinux with SRV is ok. Access to the scsi hd
> without problems.
Ok.
So, AIC7xxx is your SCSI driver, right?
> Loading stops with : "Kernel panic: VFS: Unable to mount root fs
> on 08:03 "
Here, I stop to understand: what flavor of muLinux is that?
Sorry, but I know hundred of paths that all reach a point like that.
This is a cloned flavor or this is the InstallationDisk (makefi.bat)?
> Ext2 and UMSDOS installation: the same problem.I have read the
> docs and tried, first time, to understand some scripts. But I didn't
> find the answer. Mulinux cannot find the scsi modules. Am I right?
> Every hint is welcome.
Usually, in some incarnation, you have the chance to enter in
maintenance mode. Can you mount your disk from here?
Anycase, point on that: using the InstallationDisk you can only
run the system on your SCSI disk in the purpose to make the floppy
disk set.
You can enyoy with muLinux floppy system, but if you clone EXT2 or
UMSDOS, the system cannot works properly. It cannot mount the root fs,
because this requires AIC7xxx built-in in the kernel.
Therefore, after cloning, you have to change the mulinuz file in c:\linux
with a new kernel+aic7xxx. This is the crude reality.
Another valid alternative is that (long explanation):
------------------------------------------------------
1) boot from floppy-MU+SRV
2) "setup scsi CARD=aic7xxx" and "setup -s lock"
3) mkdir /lib/modules/boot
4) copy in the directory /lib/modules/boot this kernel modules:
scsi_mod,aic7xx, sd_mod, sr_mod, sg
You will find them in /lib/modules/preferred/scsi. (I'm not sure
if the free-size in / is enough for that: in this case, try
to cancel something in /usr/bin ).
5) Create a file /lib/modules/boot/list containing, one for line, this
modules
Ok: we patched a system in RAM, but no problem: the cloning process will
reproduce him permanently in the HD.
6) Now, you can clone. But you must select a flavor on MU that starts
using RAMDISK (no EXT2, no UMSDOS). The only remaining is the LOOP
cloning. It uses a little ramdisk, then mount via loopfs a big file in
your SCSI hd. (But also El-Torito cloning is OK).
Note
-----
let me explain better the little theory. When Linux mount its rootfs,
it has to support the media where the fs is. But mulinuz has SCSI
support in an external module. Ergo: it cannot mount EXT2 or UMSDOS
on a SCSI hd. This will requires a mega-kernel that doesn't fits on a fd.
But mulinuz can mount a RAMDISK, because ramdisk's support is *not*
modularized in MU (but it might be, in general). So, it *first* mount
its rootfs as ramdisk, then it run my script "linuxrc" (tree/setup/rc/linuxrc),
finally it mount the "real-root" (your scsi hd).
As you can see, the aic7xxx module is loaded in memory by "linuxrc":
/etc/rc/linuxrc -> /etc/rc/mount_root -> /etc/rc/modules
(This feature was designed for the InstallerDisk, but it is usually
inactive on other MU incarnations. That should be an improvement?)
Please: take a look to these scripts and, if my procedure fails, try
to modify yourself. After cloning, any changes will be reflected on
the destination.
Hope this useful for you, mon ami.
-Michele
P.S.
You surely are asking yourself why muLinux is such complex, such involved
beast; but muLinux was designed to run in RAM; kernel contains only
the minimum. How muLinux can load a module if the module resides on
a unsupported medium? Debian, Suse, Mandrake, RedHat and other solve
the problem providing a 800K kernel and also different kernels for
differents kind of installation (see Slackware). The user is suggested
to slim the kernel with a sane recompilation, only after installing.
-- In summing up, I wish I had some kind of affirmative message to leave you with, I don't. Would you take two negative messages? - Woody Allen --------------------------------------------------------------------- To unsubscribe, e-mail: mulinux-unsubscribe@sunsite.dk For additional commands, e-mail: mulinux-help@sunsite.dk
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