Arch Linux

Yannovitch

Member

Registered: 2011-12-08

Posts: 1

LVM inside domU

Hello,

I'm running Xen on my ArchLinux (which run on a dedicated server), and I have some domUs running.
LVM run on my dom0 for the part of the hard drive dedicated to the domUs.
However, I need for one of my domU to have LVM running inside to manage "sub domU".

To achieve that goal, I tried to create a virtual device inside my LVM, to do a "LVM inside LVM" with "device-mapper create mysubdevice file-of-definition".
But I don't know how to do that well, because I don't want to have LVM on my whole disk, just on a special part, so with this definition :

50780540 419649500 linear /dev/my_LVM/ 0

it give me this error :

 device-mapper: table: 252:5: linear: Gap in table 

.

I know it's due to me not having the begin at 0 but at 50780540, but I don't know how to proceed without having the whole disk used by LVM ?

Maybe I'm misthinking the problem and I should do the LVM part from the dom0, with an other VG for example.
At least, it could allow me to easily see what's inside the domUs LVM.
But I'm really worried of the LVM getting inconsistent.

What do you think of my problem ?

Yann
(Sorry for the mistakes, i'm french)