LVM without LVMtools

Where I can know about co-operation LVM tools and kernels?

Whether it is possible to activate LVs (lvchange -a y) without a package LVM?

The tools read and interpret metadata stored on the physical devices, or in the file system. They use this data to instruct the kernel device-mapper to create mapped devices that correspond to the volumes described in the metadata using the device-mapper ioctl interface (via libdevmapper).

See Alasdair's talks for more information on how all the pieces fit together:

http://people.redhat.com/agk/talks/

Regards,
Bryn.