topic Re: urgent! modules at boot time! in Operating System - Linux

urgent! modules at boot time!

Max_4 — Fri, 13 Sep 2002 17:07:22 GMT

Hi all,

I have two machines running Red Hat 7.2. One of them when it boots, automatically loads the module required to handle a disk array (cciss.o) and the other machine does not! I have to modprobe the module
manually in order for the machine to have it loaded...

This is critical because without this module I can't mount the filesystems on the disk array which have an Oracle DB on them!

Both /etc/modules.conf are the same on both machines... and I still trying to find a difference between them to see why this is happening...

Can somebody help me with this? Also Could somebody explain how is the module dinamic loading process when a machine boots?
What do I need to set up in order to have a machine automatically load a module when it boots?

Thanks a lot in advance!

Re: urgent! modules at boot time!

Kodjo Agbenu — Fri, 13 Sep 2002 18:57:45 GMT

I guess (but I'm not sure) one was installed with the disk array connected, but on the other wone, you connected the array afterwards.

Normally, modules for critical hardware such as disks are loaded in initial ramdisk (initrd).
Some people use "mkinitrd" to have it re-created, but I prefer manual method. Let's say your running kernel version is 2.4.9-31

cp /boot/initrd-2.4.9-31.img /tmp/initrd.gz
gunzip /tmp/initrd.gz
mount -oloop /tmp/initrd /mnt
cp -p /lib/modules/2.4.9-31/kernel/drivers/scsi/cciss.o /mnt/lib

Edit /mnt/linuxrc and add :

insmod /lib/cciss.o

cd /boot
umount /mnt
gzip /tmp/initrd
mv /boot/initrd-2.4.9.img /boot/initrd-2.4.9.img.old
mv /tmp/initrd.gz /boot/initrd-2.4.9.img
/sbin/lilo

Good luck.

Kodjo

Re: urgent! modules at boot time!

Max_4 — Fri, 13 Sep 2002 21:19:17 GMT

Thank you very much Kodjo,

I think this will solve the issue.
I have compared the linuxrc of both servers and have found that the one
with the problem is missing the cciss.o module under /mnt/lib and also missing its correspondent insmod.

I have not yet implemented the whole procedure, because this is a critical production system and I'd like to try it first on a non-production system before.

I have another question in one of the systems I had trouble finding the running kernel version, because I found the following under /boot

# ll /boot/vmlinuz lrwxrwxrwx 1 root root 16 Nov 30 2001 /boot/vmlinuz -> vmlinuz-2.4.7-10

vmlinuz is a symbolic link to vmlinuz-2.4.7-10. But when you do:

#uname -r
2.4.7-10smp

So which could be the right kernel version?

Thank you very much again in advance...

Re: urgent! modules at boot time!

Kodjo Agbenu — Fri, 13 Sep 2002 21:54:15 GMT

Hello,

Normally, "uname -r" gives you the right version. The name of kernel file in /boot can be anything you want.

You can compare "uname -r" with the result of "depmod -av".

Good luck.

Kodjo