Compute with external storage

This deployment scenario uses block storage provided by an external storage array over iSCSI. The first three nodes are management nodes; they run a small internal Virtuozzo Storage for the system only, and the compute controller. Worker nodes are compute-only.

Cluster layout

Compute worker	Compute worker	Compute worker	Compute worker	Compute worker
Compute controller	Compute controller	Compute controller
Storage (system)	Storage (system)	Storage (system)
Management	Management	Management
External storage array connected to all nodes over iSCSI
Node1	Node2	Node3	Node4	Node5
Bond 1 (Storage) 2 × 25 GbE LACP Non-routable, MTU 9000	Storage (system) · Internal management · iSCSI (to external array)
Bond 2 (Overlay + Public) 2 × 10 GbE LACP VLAN-tagged, public via NAT	VM private (VXLAN) · VM public · Admin panel · Compute API · SSH

Storage policy

Compute-only worker nodes have no local storage or metadata role. Provide block storage over iSCSI and size their NICs for storage traffic. Virtuozzo Storage still requires at least three storage disks across the cluster on the management/storage nodes, even though VM data lives on the external array.

Per-node hardware

Resource	Management node		Worker node
	Minimum	Recommended	Minimum	Recommended
CPU cores (physical)	16	32+	16	32+
RAM (ECC, required)	32 GB	96 GB+	32 GB	128 GB+
System disk	120 GB SSD	2 × 480 GB SSD (RAID-1)	120 GB SSD	2 × 240 GB SSD (RAID-1)
Metadata (MDS)	On system disk (combined), first 5 nodes		On system disk (combined), first 5 nodes
Storage disks	At least one for internal Virtuozzo Storage		Not applicable (VM data is on the external array over iSCSI)
Backend network	2 × 10 GbE (LACP)	2 × 25 GbE (LACP)	2 × 10 GbE (LACP, incl. iSCSI)	2 × 25 GbE (LACP, incl. iSCSI)
Frontend network	10 GbE	2 × 10 GbE (LACP)	10 GbE	2 × 10 GbE (LACP)