The Croatian scientific and educational cloud (HR-ZOO) project led by SRCE provides a long-term advanced computing and storage resources and network connectivity for Croatian scientific and academic community. One of HR-ZOO components is cloud infrastructure for advanced computing based on open source platform OpenStack. SRCE deployed OpenStack on over 90 KVM-based hypervisors with over 11.000 CPU cores with NVIDIA GPUs and NVMe SSD drives. Storage is based on Ceph and provides two pools – one based on hard drives with 3 PB raw capacity and one based on NVMe SSD drives with 400 TB raw capacity. In this talk we will present our adventures in deploying this infrastructure.