Creating raw device mapping disks

If the hypervisor supports raw device mapping (RDM) disks, then RDM is an option when you are creating disks for a virtual machine. See Creating pass-through SCSI disks if the hypervisor uses a pass-through SCSI disk.

Note: With VMware systems, ESI does not support expanding RDM disks that are attached with virtual compatibility mode.

To create one or more RDM disks:

  1. In the left pane of the ESI window, select the host.

  2. In the Actions pane, click Create Disk.

  3. The Create Disk wizard appears.

  4. Select Raw Device Mapping as the disk type, and then click Next.

  5. In the Storage System page, select the storage system, and then click Next.

  6. In the Storage Pool page, select the storage pool, and then click Next.

  7. In the New LUN page, set the details for the new disk or disks, and then click Next.



LUN Count

Number of disks to be created

Sequence Number

First number to append to the name for the first LUN

Note: For example,  to create three LUNs with the appended numbers 15, 16, and 17, type 3 in the LUN Count field and type 15 in the Sequence Number field.


Name of the disk or disks


Description for the disk or disks


Size and unit of measurement for each disk

Service Node

Storage processor that hosts the disk or disks

Provision Type

Select either Thick or Thin

Stop provisioning new LUNs when error occurs

To stop creating new LUNs if an error occurs during the process

  1. In the hypervisor settings page, set the following field values, and then click Next.

Note: For hypervisors, ESI does not support creating SCSI controllers. However, ESI uses existing SCSI controllers to create disks for virtual machines.




SCSI controller


SCSI controller location

RDM Compatibility Mode

The type of compatibility (physical or virtual)

Note: If you select Physical in the RDM Compatibility field, the guest operating system can access the hardware directly.


Types include:

  • Persistent: Changes are immediately and permanently written to the disks.

  • Independent Persistent: Independent disks are not affected by snapshots.

  • Independent Non Persistent: Changes to disks are discarded when you shut down your system or revert to the snapshot.

Note: With Physical mode, Persistent is the only available option.

Disk Provisioning

Options if you create a virtual disk:

  • Thick Provision Eager Zeroed: All disk space is allocated and any previous content is deleted when the disk is created; this option may take longer than the other two options.

  • Thick Provision Lazy Zeroed: All disk space is allocated but existing content is not deleted when the disk is created.

  • Thin Provision: Allocates only the disk space that is currently needed.

  1. In the Disk Preparations Settings page, set the following field values for the disk or disks, and then click Next.



Partition Type

Type of partition to be created, either MBR (Master Boot Record) or GPT (GUID Partition Table)

Volume Size

Disk volume size

File System

  • Partition Type of MBR: Either NTFS (New Technology File System) or FAT32 (File Allocation Table 32 bit)

  • Partition Type of GPT: NTFS, the only available choice

Allocation Unit Size

Size of the allocation unit measured in bytes

Volume Label

Label for the volume

Drive letter or mount path

Drive letter or a mount path to the disk

  1. In the Review Input Parameters page, review the settings, and then click Next to confirm them.

  1. In the Progress page, click Next.

Note: Click More Information for more progress details. If a problem occurs while you are connecting a disk, an error message appears along with options to resume or roll back the process. After the error is resolved, click Resume to resume the process. Click Rollback to revert to the previously executed step.

  1. In the Summary page, click Finish.

  2. The disk appears in the list of Host Disks for the specific host and in the LUNs list under Storage Systems.


Related links


 Creating disks

 ESI overview

 Creating disks for virtual machines

 Home window

 Creating SCSI disks


 Creating virtual disks


 Creating pass-through SCSI disks


 Viewing host disks


 Connecting disks


 Disconnecting disks


 Deleting disks


 Expanding disks