Re: [linux-lvm] Severe problem: data lost while adding a partition

[Sander Alberink <alberink@stamppot.demon.nl>]

Hi all,

Thanks for the reply. At the moment I have re-initialized the PV's via 
pvcreate -ff. However, trying to reconstruct a new volume group yields 
me the following output:

# vgcreate -v home /dev/hda[1,4,6,7]
vgcreate -- checking volume group name
vgcreate -- checking volume group directory existence
vgcreate -- locking logical volume manager
vgcreate -- checking volume group "home" existence
vgcreate -- counting all existing volume groups
vgcreate -- reading all physical volume data from disks
vgcreate -- checking if all given physical volumes in command line are new
vgcreate -- checking physical volumes name "/dev/hda1"
vgcreate -- checking physical volumes name "/dev/hda4"
vgcreate -- checking physical volumes name "/dev/hda6"
vgcreate -- checking physical volumes name "/dev/hda7"
vgcreate -- no valid physical volumes in command line
#

So apparently something is not OK. But what can that be? Any pointers 
would be appreciated!

>> I really appreciate your help in this. However, I am rather reluctant to
>> dive in and be hasty in my commands. I really don't want to destroy my
>> data.... As I understand it, pvcreate -ff would re-initialize the
>> physical volume. As I understand it, I will have to add them to a volume
>> group again. But will the filesystem still be intact after that then?
>>
>> Sorry if this sound like a beginner question to you. It very well might
>> be, but I'd rather be careful....
>
>
> Thing to understand is that LVM commands update a small
> header on the phyiscal volume. You can munge the LVM
> portion without touching your data at all. In this case
> the data has no way of knowing that anything happend to
> the LVM portion of life: they live in entirely different
> parts of the disk drive. 


Best regards,

Sander Alberink