This post explains why when adding a 4K LUN as an RDM to a VM doesn't work
Symptom:
When a 4K block sized LUN is added to a virtual machine on an ESXi 5.5 environment you get the below error when trying to boot the VM.
Resolution:
Either recreate the Volume/LUN to one that is 512, upgrade vCenter and your ESXi hosts to version 6 or higher. In our case we were trying to P2V the OS of a SQL server and then move over the direct attached LUN to the VM. We had to back out our change since we were still on ESXi 5.5.
Cause:
As designed. VMWare doesn't support 4k LUNs until after ESXi 6.
SageLike Post ID: SL0017
Applies to:
ESXi 5.5 and earlier
References:
https://gruffdba.wordpress.com/2015/08/02/4k-logical-block-size-size-fails-on-vmware/
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2091600
