You need describe your LVM volume group in XML format:
vgs
vi /etc/libvirt/storage/vg_server1.xml
virsh pool-define /etc/libvirt/storage/vg_server1.xml
virsh pool-start vg1
virsh pool-autostart vg1
virsh pool-info vg1
now use virt-instal:
virt-install -d --hvm --vnc --name=server1 --ram 5000 --disk pool=vg1,size=100,bus=virtio,cache=none --network network=default,model=virtio \
--location=http://mirror.duomenucentras.lt/centos/7/os/x86_64/ \
--os-type=linux