Hello, friend!

1. What is RDM?
Raw device mapping (RDM) provides a mechanism for a virtual machine to have direct access to a LUN on the physical storage subsystem (Fibre Channel or iSCSI only). An RDM is a mapping file in a separate VMFS volume that acts as a proxy for a raw physical storage device. The RDM allows a virtual machine to directly access and use the storage device. The RDM contains metadata for managing and redirecting disk access to the physical device.The file gives you some of the advantages of direct access to a physical device while keeping some advantages of a virtual disk in VMFS. As a result, it merges VMFS manageability with raw device access.RDMs can be described in terms such as mapping a raw device into a datastore, mapping a system LUN, or mapping a disk file to a physical disk volume. All these terms refer to RDMs.

2. Which OSs support the FusionCompute RDM function?
You can query the VM OSs supported by FusionSphere by visiting:
https://doc.hcs.huawei.com/solution-cqs-gw/#/cqs


For details about the OSs that support the FusionCompute RDM function, see the descriptions of disks that support SCSI (virtio-scsi) listed in FusionSphere SIA Huawei Guest OS Compatibility Guide (KVM Enterprise Virtualization) in the x86 architecture or FusionSphere SIA Huawei Guest OS Compatibility Guide (ARM) in the ARM architecture.

Best regards!