Setting storage for virtual machines

Virtual machines use block storage and file storage.

Block-mode storage through the ocs-storagecluster-ceph-rbd-virtualization storage class is recommended as it provides optimized performance for block IO.

However, for Windows VMs, it is always recommended to use ocs-storagecluster-ceph-rbd-virtualization storage class. If you use the ocs-storagecluster-ceph-rbd storage class, then Windows VMs may report bad CRC or signature errors due to I/O patterns. The performance of the cluster performance can degrade due to excessive re-transmissions caused by CRC errors that leads to network saturation.

VMs must request RWX storage so that they can be moved between nodes non-disruptively using Live Migration.

• File storage is supported for virtual machines, but it lacks the performance advantage of block storage.
• RWO volumes are supported for virtual machines but are not recommended, as they block Live Migration. VMs using RWO volumes cannot move between nodes without causing disruption.

For more information about live migration, see Live migration for virtual machines.

Fusion Data Foundation can be configured for encryption, with keys managed within the OpenShift cluster or by an external Key Management Service (KMS). For more information about encryption, see Preparing to connect to an external KMS server in Fusion Data Foundation.