An odd one...

[Frode Petersen]

Mikkel L. Ellertson skrev:
> Frode Petersen wrote:
>> 1)
>> I didn't change the kernel or the (memory?) image file, and I suspect
>> that might be one reason. Are there hardcoded references to partitions
>> in these files, so that the reference in grub.conf is used only to find
>> the kernel, and not tell the kernel where to find and mount the other
>> partitions? Has the kernel an 'image' of the disk system on which it is
>> compiled?
>>
> The /boot/initrd-<version>.img file has information on the LVG
> configuration, so if that is changing, you need to build a new
> initrd file. man mkinitrd for more information.

Is that info related to names of partitions only, or to location on the 
disk also? I suspect the first, which would mean that I could use the 
tool you mention further down to move things around, ending up with an 
identical partitioning scheme even if I 'slide' the partitions over a 
bit on the physical disk. Or am I wrong?

>> 2)
>> The /dev/root special file (as all other special files in /dev were not
>> copied over. I tried, but gave up. The command I used was
>>
>>     cp -P --copy-contents /dev/root .
>> but after some minutes, the copy had grown to several GB, so I aborted
>> and deleted the file. The copying probably got caught in some circular
>> recursiveness.
>> I know the special files are neccesary, but are they generated on the
>> fly by the kernel, or do I have to do it manually? And would the lack of
>> them in it self cause the kernel panic?
>>
> The contents of the /dev directory are created on the fly once udev
> is started. If you look at /proc/mounts, you will see an entry:
> /dev /dev tmpfs rw 0 0
> You do not see it when running mount, probably because it was
> mounted before /etc was read/write. But there are a few entries that
> are in the /dev directory that are needed before the dev file system
> is mounted. The best way I have found to copy them is to boot from a
> live CD, mount the file systems, and copy that way.
> 
> You also do NOT want to use the --copy-contents option when trying
> to copy device entries. You were trying to copy the contents of the
> drive partitions, and not the device entry. On top of that, the
> "contents" of some device entries appear to be infinite. (/dev/zero
> and /dev/random for example.)

I saw a warning about those devices, but thought that /dev/root was 
different. Why, I don't know. Lesson learned, I guess..

> As a side note, you can use cp to copy a disk partition, but it is
> not usually a good idea. This is especially true for a partition
> mounted r/w. (I prefer using dd over cp when doing that type of
> copy. Things like "dd if=/dev/fd0 of=floppy.img" can be handy.)

Is it safe to have both if and of point to a partition, or should I go 
with the intermediate image file?

>> 3)
>> I have to add more entries to the grub.conf entry.
>>
>> 4)
>> Something I haven't thought of at all.
>>
>> I'll probably just reinstall FC6 from scratch, but if someone comes up
>> with an idea on how to proceed, I'll try it out first. I just consider
>> this as a learning opportunity.
>>
> If you want the learning experence, get the System Rescue CD. It can
> handle LVM, but unless you copy /etc/lvm/lvm.conf to something like
> a USB drive or floppy, you will have to use the lvm tools to
> generate the information.

Thanks for the warning and the tip. I have fetched it and will try it out.

> 
> http://www.sysresccd.org/
> 
> Mikkel

Thank you for the help with this. I had thought it was a lost cause, but 
I'll see what is to be learned from all this.

Frode