WWN ID of a VMFS virtual disk

[srini7]

We have a configuration where multiple VMware virtual machines(VM) form a cluster and they are sharing a virtual disk created on VMFS datastore. As part of cluster management operations, cluster requires to validate the WWN ID of a virtual disk created on VMFS datastore. To get WWN ID, we use SG_IO scsi ioctl call. Unfortunately we are unable to get the WWN ID of a virtual disk inside of virtual machine running Redhat Enteripise Linux 6.4 version. The attached figure shows the configuration we have.


Could you please let us know if there is any method such as SCSI ioctl command available to get the WWN ID of the virtual disk from the VMware guest OS?


If it is not possible to get the WWN ID of the virtual disk from the VMware guest OS, is there any other identifier(UUID or something else) which can be used from VMware guest virtual machine to uniquely identify the virtual disk? 

[virtualdive]

Hi Srini,

You have used word 'Cluster' many times in your question, but not sure which cluster you are talking about here. Is it MSCS cluster or VMware HA/DRS clusters, I guess the first one.

WWNs is used for HBA's on the EXi host, when you say WWN's of virtual disk, are you referring to NPIV?

Thanks,

[srini7]

Hi,

Thanks for your reply.

As you pointed out, it is not VMware HA cluster. What we need is a method to uniquely identify "virtual disks" carved out of a VMFS datastore which are "shared among multiple VMs" (irrespective of the cluster).

For example, in case of RDM disks, we can identify the disks based on the WWN IDs obtained using SCSI ioctl calls. On similar lines, we need a way to uniquely identify virtual disks using WWN ID or any other identifier.

>> WWNs is used for HBA's on the EXi host, when you say WWN's of virtual disk, are you referring to NPIV?
No. I am not referring to NPIV since NPIV cannot be configured for VMFS virtual disks.

Thanks.