To tested out the software defined storage performance in the MS cluster environment.We have created the RDM LUN with different LUN ID.The Clustering going to happening in the two ESXi box,so the RDM mapped with physical mode,the RDM lun’s are present to host with different LUN ID.
RDM LUN’s are presented to VM1 and while presenting to RDM LUN to VM2 run out an error “Incompatible device backing specified for device ‘0’ ”
Referred the KB 2054897
As per the KB refer the issue will happen due to inconsistent in the LUN ID.After changing the LUN with same LUN ID presented to esxi hosts and the clustering VM reconfigured.It works charm.
In refer to RDM mapping,the cormac hogan blog provides the more information on the RDM compactability testing in the different LUN ID.
Refer Link : http://cormachogan.com/2012/09/26/do-rdms-still-rely-on-lun-id/
The post most precisely explain about the RDM mapping and testing with LUN ID.Thanks for Cormac(Admired Hero) 🙂
VML- Refer to Vmware Legacy
VML has various information embedded into it.The first segment consist of the how the lun has been advice(channel,target,LUN ID) in the hex value and middle segment refer your NAA id(Network Address Authority) and last segment vendor specific information about the LUN.
NAA – encoded information of LUN presented to the host,it will contain the information about your vendor,type of storage,array number,ldev(logical Raid storage)
Refer the below mention blog to break down your NAA ID