Node conditions describe the status of all worker nodes and are used to check the environment settings of worker nodes to identify potential issues before any system impact.

Node conditions:

• Ready:
  Indicates that the node is ready for Longhorn operations, including that a longhorn-manager pod is running on this node, the Kubernetes node is ready, and there is no physical resources pressure.

• Schedulable:
  Indicated that the node is not cordoned and workload can be scheduled to this node.

• MountPropagation:
  Indicates that the node supports mount propagation. This is necessary for sharing of volumes mounted by a container with other containers in the same Longhorn pod, or to other Longhorn pods on the same node.

• Multipathd:
  Confirms if the multipathd service is not running on the node, which may affect the pod with the volume startup. See Troubleshooting: MountVolume.SetUp failed for volume due to multipathd on the node.

• RequiredPackages:
  Checks if all required packages (NFS client, iSCSI tool, cryptsetup, dmsetup) exist for Longhorn

• NFSClientInstalled:
  Identifies if any of the following NFS clients are supported: v4.2, v4.1, or v4.0. NFS client is required for RWX volume and backup.

• KernelModulesLoaded:
  Identifies if the following Kernel modules are loaded:

  • dm_crypt: Is required for the volume and backing image encryption.

• HugePagesAvailable: Indicates whether the node is properly configured with HugePages (2Mi) as required by the Longhorn v2 data engine. This includes verifying that:

  • HugePages (2Mi) are registered as a Kubernetes resource (hugepages-2Mi).
  • The configured HugePages capacity meets or exceeds the value defined in the v2-data-engine-hugepage-limit setting.

Node conditions do not block the Longhorn deployment but they result in warnings in the Longhorn Node resource. For more information, see Longhorn Installation Requirements.