zfs create -V 10G rpool/xen/dilos01

For installation we need 2GB RAM. After installation we can use less if needed.

virt-install -p --name=dilos01 --ram=2048 --network bridge  --disk path=/dev/zvol/dsk/rpool/xen/dilos01,driver=phy --vcpu=2 --location /xen/dilos-1.3.4-i386.iso --nographics