Re: Upgrading Sarge to Etch - failing to boot new kernel

[Piotrek Gliźniewicz <glizda@gmail.com>]

> Hi,
>
> the best is to not use the (I call it "deprecated") old-style linux device names. Use /dev/disk/by-uuid/.... for the specification of the root filesystem (each filesystem has a unique ID assigned on creation). Alternatively assign a name to the file system using tune2fs/e2label and specify as /dev/disk/by-name/...., so it has a nice name. The management of the symbolic links in /dev is done by UDEV which is booted by the initrd.
>
> Here is my aboot config of the kernel line on my AlphaStation (should be similar with MILO):
>
> 0:2/vmlinuz ro initrd=/initrd.img root=/dev/disk/by-label/root
>
> These directory listings are dynamically created by UDEV, so you should prefer these ones. Recent installations of Ubuntu (not sure if also Debian) automatically use them:
>
> thetaphi@alpha:~$ ls -l /dev/disk/by-label/ insgesamt 0 lrwxrwxrwx 1 root root 10  8. Jun 07:27 boot ->  ../../sda2 lrwxrwxrwx 1 root root 10  8. Jun 07:27 root ->  ../../sdb1
>
> thetaphi@alpha:~$ ls -l /dev/disk/by-uuid/ insgesamt 0 lrwxrwxrwx 1 root root 10  8. Jun 07:27 09311049-3762-4d4d-877e-a4b02a4db4f1 ->  ../../sdb1 lrwxrwxrwx 1 root root 10  8. Jun 07:27 b8c0bb84-297a-44e5-b83e-d7aa1e352248 ->  ../../sda2
>
> If you have multiple network cards it's also a good idea to assign static names using UDEV configuration based on their MAC address, ethX is ugly :-)
>
> > So, the upgrade to Lenny went without problems. It also installed
> > automatically the 2.6.26. The problem with 2.6.26 is, it panics because it can't
> > find my SCSI drive (the 2.6.18 still boots fine). It will print the message to add
> > the correct 'root' parameter, then the available partitions message, after
> > which it doesn't print any. I assume something has changed in the order
> > things are initialized? I found this:
> > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=323885
> > Tried mv /etc/rcS.d/S40hotplug /etc/rcS.d/S25hotplug but it didn't work
> > (neither proceeds further nor prints any available partitions). I also know,
> > that IDE drives where moved from hda... to sda..., so I expect to find what
> > previously was /dev/sdb7 at /dev/sdf7, but setting this as root does not help.
> > Any clue what should be done now?
I've tried the uuid approach - the effect is the same - 2.6.18 runs, 
2.6.26. But I managed to find the real issue. MILO fails to load the 
initrd image: "initdisk too large, would overwrite kernel.", apparently 
the same issue as described here:
http://lists.debian.org/debian-alpha/2002/04/msg00157.html
I took a look at MILO source and it seems the LOADER_AT in Makefile 
should be changed (the image has to fit between the kernel and LOADER_AT 
address, at least that's what I understood). But there's a comment, that 
other code depends on it, so I won't even try to touch this. The other 
solution would be to build a custom smaller kernel, but this will have 
to wait until I have more time.
Anyway, thanks for help.
Best,
--
piotrek