Your other system is not aware of the existence of the volume group that contains the logical volume you want to mount.
You'll want to do a "vgscan" to get your system to scan the headers of the disk and "become aware" of what volume groups exist, then you'll want to use the "vgimport" command (see man page for usage) to actually make that volume group part of your system. Then you should be able to mount it.
You'll want to do a "vgscan" to get your system to scan the headers of the disk and "become aware" of what volume groups exist, then you'll want to use the "vgimport" command (see man page for usage) to actually make that volume group part of your system. Then you should be able to mount it.