[linux-lvm] LVM seems to break tar and cp "stay-local" option s

[Jakma, Paul]

> Hi Paul,
> 
> what about:
> 
> cd /
> find . -print > /home/root/list
> vi list (edit to fit your wishes)
> tar -cvf- . -T /home/root/list | (cd /mynewroot; tar -xvf-)
> 
> (you might want to check the tar option for "read list from file" - it
> seems to differ between distributions)
> 

possible, and i did something similar in the end, eg  .... tar ... /bin /dev
/sbin ...

But the point is, why do these userland tools not recognise the boundary
between fs on ordinary device, and fs on lvm?

Also, another little issue, about partitioning: 

if you change the partition table with fdisk, the kernel will not update
it's in-core idea of the partition layout if any of the partitions on that
disk are in-use, eg mounted fs or swap.

However, the kernel doesn't seem to recognise partitions that are active LVM
PV's as marking that disk in use. Ie i can repartition a disk in-use by LVM,
and the kernel does not seem to know that the disk is busy and hence will
commit the new partition table to memory.

I have a feeling LVM is forgetting to set some kind of flag that marks a
physical disk device as in-use. (and this might be related to the tar/cp
"stay-local" problem aswell). However i am not a kernel hacker... :)

regards,

Paul Jakma.