[linux-lvm] creating snapshot

[Arianto C Nugroho]

Hi ...

I'm trying to create a read-only snapshot for backup purpose, but i'm 
getting this error :

snapshot: Required device-mapper target(s) not detected in your kernel

problem is i already compiled the device-mapper inside the kernel (not 
as module).

I'm using a debian sarge and linux-2.6.12 kernel.

What seems to be the problem ??

Thanks before for any help.