NVMe devices

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PCIe-attached NVMe devices are available for IBM® LinuxONE as of LinuxONE II. NVMe devices can be virtualized as virtio block devices.

To provide NVMe devices as virtual block devices to a virtual server:
  1. Set up the NVMe devices, see Preparing NVMe devices.

    Provide device nodes that persist across host reboots.

    Standard device nodes of the form /dev/nvme<i>n<n> do not persist across host reboots. Persistent device nodes, typically, include information that identifies the physical resources for the device. Depending on your host setup, udev might create suitable nodes that include the PCI function address of the NVMe device, for example /dev/disk/by-path/pci-<function_address>-nvme-<n>.

    For live migration of a virtual server, device nodes must be such that they addresses equivalent resources on both the source and destination host. Migration of the virtio block device is then possible through disk migration, see step 3.c in Performing a live migration.

  2. Configure the NVMe devices as virtual block devices.

    Configure devices that are to be defined with the virtual server in its domain configuration-XML file. Alternatively, you can define devices in a separate device configuration-XML file. Such devices can be attached to an already defined virtual server.

The following graphic illustrates PCIe-attached NVMe devices on the host and the corresponding block devices on the guest.
Figure 1. NVMe devices configured as virtual block devices

This graphic shows how NVMe devices are addressed by function address on the host and through a device bus-ID on the guest