TigerRool10-1 ,
I understand your concern. However , Read cahce is an extension of controller cache , addition or deletion of read cache should not affect data access.
Also , VMware 6.7 is not supported on MSA 2040.
Please refer to the below link for the list of supported OS
https://downloads.hpe.com/pub/softlib2/software1/pubsw-linux/p1158764188/v144456/723983-006.html
I am an HPE Employee