Yes it is a ISO install. I've installed a few things: bind, dhcpd and SEP Sesam Server, then I've changed the default mounts to:
/dev/mapper/pve01-root on / type xfs (rw,noatime)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on...