Re: boot problems - initrd

Hi Jeremy,

> Hello,
>
> After forgetting my root password and trying to boot into single user
> mode under Red Hat 7.2 Pro (boxed retail set) I have run into a kernel
> panic. In grub I edited the boot commands to include "kernel /boot/....
> single". Immediately after doing this the system failed to boot with the
> error message "kernel panic: no init found. Try passing init= to
> kernel". (Previously the machine had run just fine and had been up for
> over 150 days). After the first failure I tried adding any combination
> of "single", "-single", "s", and "-s" I could think of, and changed
> their position in the command (first/last parameter, appended "single"
> to other commands including initrd line). Nothing could get me into
> single user mode, I never got past the kernel panic. I also tried
> passing init= as a kernel argument with the path listed on the "initrd"
> command. I eventfully booted to rescue mode from a RH 7.2 install disk
> and got my password changed. However, I am still unable to boot from the
> hard drives. (In a software RAID 1 config)

There's alot of information here... thanks :) Can you give us a little
more? Dual or single cpu, kernel version? Filesystem layout, contents of
fstab?

For future reference, there is a way around losing or forgetting your root
password. Add your username to the wheel gorup, and edit the pam.d/su file
so only your user can su root and is implicitly trusted (uncomment the two
lines referencing the wheel group in the su file). Then you can just "su
-" into root without a password, but only as that user.

> My grub.conf file contains the following:
> root (hd0,0)
> kernel /boot/vmlinuz-2.4.7-10 ro root=/dev/sda1
> initrd /boot/initrd-2.4.7-10.img
>
> ( I set the file back to exactly how it looked when I started, any
> changes I made were always lost after having to reboot)

Have you tried uninstalling grub and running lilo? (make a backup of
grub.conf first)

> Also of interest is an error that occurred just before the kernel panic.
> It read "pivotroot: pivot_root(/sysroot, /sysroot/initd) failed:2". Does
> anyone know what the "2" error code indicates? I cannot find this
> anywhere in any documentation of pivot_root. It seems to be a rather
> obscure function in the first place.

Best to check with the folks at kernel.org on this for the best advise.
The kernle and init processes are complex.

>>From research I have done online, I have found other posts mentioning
>> this exact problem. However, none of them have any solutions. It was
>> suggested that this may be due to file system corruption. I doubt this
>> is the case as I can mount my software RAID 1 drives from rescue mode
>> and read/write all the files just fine. Everything seems to be intact.
>> I have not run fsck but I will do that ASAP.

Well, everything listed maybe, but there is still the mbr that can get
corrupted too....
>
> I have gotten my hands on the latest RH 8.0 ISOs. Could upgrading from
> 7.2 to 8.0 cure my woes? Would this just preserve the hardware/device
> misconfiguration?

A new kernel might improve it in any event.

<snip>

Good luck
-- 
Keith Mastin
BeechTree Information Technology Services Inc.
Toronto, Canada
(416)696 6070