[linux-lvm] shift PV from disk to raid device?

Kai Schaetzl maillists at conactive.com
Tue Dec 9 20:49:40 UTC 2008

Doug Ledford wrote on Tue, 09 Dec 2008 14:56:24 -0500:

> One thing that might be happening here (and I'm not sure since I'm not
> an LVM expert) is that when the lvm stack finds the pv on /dev/sdb3
> or /dev/sda3, it sees a full size partition (meaning it can access all
> the way to the end of the device).

But this couldn't normally happen if I just created LVM on top of the md 
device, correct? However, as I created a PV on /dev/sda3, did not remove 
it and then create the md array on it and then the PV on the md device 
there might be something going on ... especially in case the array broke.

> The solution to this problem is to create the raid device with a
> superblock format of 1.1 or 1.2 (aka, -e 1.1 or -e 1.2).

man mdadm gives the difference between 1.1 and 1.2 as 1.2 putting the RAID 
superblock 4k after the beginning. Is this another measure against 
accidental overwrites? Would you recommend 1.2 if I were to use a newer 
superblock version?


Kai Schätzl, Berlin, Germany
Get your web at Conactive Internet Services: http://www.conactive.com

More information about the linux-lvm mailing list