Creating an RDM LUN on a guest OS

You can use SnapDrive to create FC, iSCSI, or ESX iSCSI accessed RDM LUNs on a guest OS.

Before you begin

Create the dedicated volumes to hold your LUNs on the storage system.
Verify that the FC or iSCSI service has been started on the storage system.
Before creating a LUN in a VMware guest OS, you must manually create initiator groups by using System Manager, FilerView, or at the storage system console.
When you create a shared FC or iSCSI RDM LUN, you must choose an initiator from each ESX server to create a single initiator group automatically using SnapDrive.

Steps

Perform the following actions to launch the Create Disk wizard:
1. Select the SnapDrive instance for which you want to create a disk.
2. Select Disks.
3. From the menu choices at the top of MMC, navigate to Action > Create Disk .
The Create Disk Wizard is launched.
In the Create Disk Wizard, click Next.
The Provide Storage System Name, LUN Path and Name panel is displayed.
In the Provide a Storage System Name, LUN Path and Name panel, perform the following actions:
1. In the “Storage System Name” field, type the storage system name where the LUN will be created or select an existing storage system using the pull-down menu.
2. In the “LUN Path” field, type the LUN path or select the path on the storage system you added in Step a.
3. In the "LUN Name" field, enter a name for the LUN and click Next.
The Select a LUN Type panel is displayed.
In the Select a LUN Type panel, select Dedicated, and then click Next.
In the Select LUN Properties panel, either select a drive letter from the list of available drive letters or type a volume mount point for the LUN you are creating. When you create a volume mount point, type the drive path that the mounted drive will use: for example, G:\mount_drive1\.
Note: The root of the volume mount point must be owned by the node on which you are creating the new disk.

Note: You can create cascading volume mount points (one mount point mounted on another mount point); however, in the case of a cascading mount point created on an MSCS shared disk, you might receive a system event warning indicating that disk dependencies might not be correctly set. This is not the case, however, as SnapDrive will create the dependencies and the mounted disks will function as expected.
While still in the Select LUN Properties panel, complete the following actions:
1. Click Limit or Do not limit for the option labeled “Do you want to limit the maximum disk size to accommodate at least one snapshot?”
  If you keep the default, Limit, which is the recommended option, the disk size limits displayed are accurate only when they first appear on the Select LUN Properties panel. When this option is selected, the following actions might interfere with the creation of at least one Snapshot copy:
  - Changing the option to Do not limit and using SnapDrive to create an additional LUN in the same storage system volume
  - Creating a LUN in the same storage system volume without using SnapDrive
  - Storing data objects other than LUNs on this storage system volume
2. Select a LUN size, which must fall within the minimum and maximum values displayed in the panel.
3. Click Next.
If the settings on the storage system volume or qtree on which you are creating the LUN do not allow SnapDrive to proceed with the create operation, the Important Properties of the Storage System Volume panel is displayed, as described in Step 7. Otherwise, Step 7 is skipped.
The Important Properties of the Storage System Volume panel displays the settings that will be used for the volume or qtree you specified in Step 4 of this procedure.
SnapDrive requires the storage system volume containing LUNs to have the following properties:
- create_ucode = on
- convert_ucode = on
- snapshot_schedule = off
Note: SnapDrive cannot proceed to create a LUN unless these settings are configured as shown. Therefore, you must accept these settings.

Note: The create_ucode and convert_ucode volume options are no longer used, but they are set to maintain backwards compatibility with older versions of SnapDrive.

Click Next.

The Select Initiators panel is displayed.
In the Initiator List pane, select an initiator for the LUN you are creating.
If you have MPIO installed, you have the option to select several FC initiators.

Note: You cannot select both iSCSI and FC initiators when creating a LUN on a guest OS.
Click Next.
The Select Initiator Group Management panel is displayed.

In the Select Initiator Group Management panel, specify whether you will use automatic or manual igroup management. If you select automatic igroup management, SnapDrive uses existing igroups or, when necessary, creates new igroups for the initiator you specified in Step 8. If you select manual igroup management, you manually choose existing igroups or create new ones as needed.

If you specify...	Then...
Automatic igroup management	Click Next. SnapDrive uses existing igroups, one igroup per initiator, or, when necessary, creates new igroups for the initiators you specified in Step 8.
Manual igroup management	Click next, and then perform the following actions: In the Select Initiator Groups panel, select from the list the igroups to which you want the new LUN to belong. Note: A LUN can be mapped to an initiator only once. OR Click Manage Igroups and for each new igroup you want to create, type a name in the Igroup Name text box, select initiators, click Create, and then click Finish to return to the Select Initiator Groups panel. Click Next. Note: The Next button will remain unavailable until the collection of selected igroups contains all the initiators you selected in Step 8.

If you specify...

Then...

Automatic igroup management

Click Next.

SnapDrive uses existing igroups, one igroup per initiator, or, when necessary, creates new igroups for the initiators you specified in Step 8.

Manual igroup management

Click next, and then perform the following actions:

In the Select Initiator Groups panel, select from the list the igroups to which you want the new LUN to belong.
Note: A LUN can be mapped to an initiator only once.

OR

Click Manage Igroups and for each new igroup you want to create, type a name in the Igroup Name text box, select initiators, click Create, and then click Finish to return to the Select Initiator Groups panel.
Click Next.

Note: The Next button will remain unavailable until the collection of selected igroups contains all the initiators you selected in Step 8.

You are done with igroup management.

In the Select a Datastore panel, perform the following steps.

If your virtual machine resides on a...	Then...
VMFS datastore	Choose either Store with Virtual Machine, which is the default, or choose Specify datastore to select a different VMFS datastore for your virtual machine disk format (VMDK) file to reside. Click Next.
NFS datastore	Choose Specify datastore to select a different VMFS datastore for your VMDK file to reside. The Store with Virtual Machine option is unavailable because a VMDK file cannot be stored on an NFS datastore. Click Next.

In the Completing the Create Disk Wizard panel, perform the following actions:
1. Verify all the settings.
  If you need to change any settings, click Back to go back to the previous Wizard panels.
2. Click Finish.
  Disk creation might take several seconds to complete. SnapDrive displays disk creation status in the lower panel of the center MMC pane.