Storage vendors might require that virtual machines with RDMs (hardware version 8) ignore SCSI INQUIRY data cached by ESXi.
Certain guest operating systems or applications run in virtual machines with RDMs display unpredictable behavior.
This behavior might be caused by cached SCSI INQUIRY data that interferes with specific guest operating systems and applications.
When the ESXi host first connects to a target storage device on a SAN, it issues the SCSI INQUIRY command to obtain basic identification data from the device. By default, ESXi caches the received SCSI INQUIRY data (Standard, page 80, and page 83) and the data remains unchanged afterwards.
scsix:y.ignoreDeviceInquiryCache = "true"
where x is the SCSI controller number and y is the SCSI target number of the RDM.
Because this parameter is configurable only on virtual machines with hardware version 8, upgrade the virtual machine prior to adding the parameter.
Enable this parameter only when your storage vendor recommends that you do so. This parameter is required for just a limited number of storage arrays and only for specific guest operating systems.