Requirements
Machine
Section titled “Machine”| Minimum | Recommended | |
|---|---|---|
| Firmware | UEFI. Legacy BIOS boot is refused. | Secure Boot on or off; both work. |
| CPU | x86_64 with Intel VT-x or AMD-V enabled, 2 cores | 4 cores or more |
| Memory | 8 GiB (the installer refuses under 6 GiB and warns under 7) | 16 GiB or more |
| OS disk | One disk, or two of the same size for a mirror | SSD or NVMe |
| Data disks | None (see the OS disk layout below) | One or more whole disks for instance volumes |
| Network | One wired NIC for management, DHCP or a static address | |
| Install medium | USB stick of 8 GB or more |
The node keeps part of the machine for itself and offers the rest to virtual machines: memory of max(6 GiB, 10% of RAM) and max(2, 6% of the CPU threads) vCPUs. On an 8 GiB machine that leaves about 2 GiB for instances. The reservation can be changed after the install; see Compute.
OS disk size
Section titled “OS disk size”Stage 1 asks how the OS disks are used:
| Layout | The OS disk holds | Smallest disk |
|---|---|---|
| System + compute tail (default) | The system, then a free tail of at least 20 GiB that becomes the first storage pool for instance volumes. | 214 GiB (230 GB) for the default system size (191 GiB); 131 GiB (141 GB) at the smallest system size (108 GiB). |
| Whole disk for the system | The system only. Instance volumes need at least one data disk. | 111 GiB (119 GB) |
The system holds swap (8 GiB), root (32 GiB) and /var, which takes most of
the rest and holds everything that grows; a quarter of the system’s space stays
free to extend them. With two disks the installer mirrors them (RAID 1), and the
smaller disk sets the sizes. Disks must have a hardware ID (/dev/disk/by-id/): NVMe, SATA, SAS and
USB disks have one; in a VM, give VirtIO disks a serial number.
Network
Section titled “Network”- Management network: the node’s NIC is wired, on a network a workstation can reach. Stage 2 of the install is served on that address.
- Floating IP range: a free IPv4 range on the LAN (a
/24is typical) for instance addresses. The LAN router needs a static route for it, with the node as the next hop. - DNS forwarding (optional): a LAN DNS server that can forward one domain to the node, so the cloud’s names resolve from the LAN.
- Internet access is not needed to install. It is used to download base images after the install, and for the public NTP pool when no other time source is set.
See Reach the cloud from your LAN for the router and DNS settings.
For a cluster
Section titled “For a cluster”Every node of a hyperconverged cluster meets the machine requirements above. A cluster adds nodes, disks for Ceph and networks between the nodes: see Before you start.