[linux-lvm] Linux LVM Physical Layout Structure

[Jonathan E Brassow]

have you tried using 'lvs --all -o+devices'?

If you look at the "devices" column, you will see a number following 
the device that indicates the start segment.   There are many 
additional arguments to pvs, vgs, and lvs that can be displayed to show 
you the allocation layout.  (I'm assuming you are talking about LVM2.)

Conversely, if you are using LVM2, you could also look at 
/etc/lvm/backup/<vgname> to read the specifics of how lv's are mapped 
on the pv's.

  brassow

On Oct 9, 2006, at 3:11 AM, Sundeep Saini wrote:

>
> HI,
> I have a query about the physical layout of the LVM. Using some 
> hexeditor i tried to find out the VGDA structure. But i am not getting 
> any specific structure at starting of PV.
> As The Volume Group Descriptor Area (VGDA) functions similar to the 
> partition table for LVM. It is stored at the beginning at the 
> beginning of each physical volume. 
>
> Earlier i worked on HP-UX LVM and i read that i impementation of LVM 
> is similar in both.
>
> I want to get the information of the PE map and if i extend some LV 
> and create 2-3 segments then how i will be able to know the PE chain.
>
> I got some structure on HDD that contain some ASCII values as the 
> output of #lvdisplay ot vgdisplay
>
> Please give some guidance to find the internal layout of LVM on HDD.
>
> Thanks in Advance
>
>
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