Hi ,

Is there any standard Procedure or Best practice envolve

As Wintel team at my end are not quite sure about the same .

Please can you share sort of document for the same ......

you need to identify them from vSphere side, Unisphere does not know nor care how they are used.

question is what is the reason of using RDM luns versus traditional VMDK ?

Hello,

That is more a vmware question than a vnx question but I’ll try to give you a few hints.

1. Performance. There are some discussions that letting the VM work on a native file system is a little bit faster than working on vmdk’s.

2. Direct scsi access. Some applications are using scsi commands to directly communicate with the device or the array. (For example gate keeper on a vmax system).

3. Data compatibility. If you assign a lun as rdm to a virtual machine and write a file system and data on it. You can, using the proper procedure, later assign this LUN to a physical server and he will be able to see and mount it. This may also be use full in certain backup environments when using array internal features like clones and snaps.

4. Some cluster setups need also direct scsi access to the devices.

Hope this helps.

Use the instructions mentioned here or commands :

http://www.vmware.com/pdf/esx25_rawdevicemapping.pdf