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  • 1.  RDM extension

    Posted Apr 15, 2015 02:25 PM


    I have Vpshere ESXi 5.1 and two VM's configured with Microsoft cluster 2008

    There is cluster disk (Physical compatible RDM's) mounted on volume mount points and then configure in cluster resource in VM's

    i want to extend the 2 TB LUN which has Physical RDM's configured in the cluster ( GPT disk in VM guest)

    My question is

    Do i need to remove and readd the pointer file after extending disk from SAN side, what i heard is, physical compatibility RDM doesn't require to remove and readd the pointer file, its require for virtual compatibility mode., is this true??

  • 2.  RE: RDM extension

  • 3.  RE: RDM extension

    Posted Apr 16, 2015 09:00 AM

    The reason i placed question in community because these articles confused me a lot

    one article says that recreate pointer file to recognise the extended space

    another article says that

    Physical compatibility mode

    Physical compatibility mode RDMs, which are also known as passthru RDMs, expose the physical properties of the mapped LUN to the guest operating system. For the guest operating system to recognize the added space to the expanded mapped LUN, perform a rescan from the ESX host, then from the guest operating system. This process does not require rebooting the virtual machine or the ESX host.

    No changes to the RDM files (.vmdk or metadata pointer) are required to take advantage of the added disk space.

    expecting and hoping correct answer

  • 4.  RE: RDM extension

    Posted Apr 16, 2015 02:29 PM

    No you dont have to remove and then re add the RDMs. You cant do it without any problems in production environments. One thing that can happen is that the VM dont show the new size on the disk when looking in summery but thats nothing to worry about. The RDM file on datastore is just a pointer to the LUN.

  • 5.  RE: RDM extension

    Posted Apr 16, 2015 04:06 PM

    Thank you very much,  I understand the link confused me but is there any way documented for cluster disk which we don't need to remove pointer file for physical compibility RDM

    have you tested anywhere, this will give us some confident.