As prerequisite to move ESXi 6.5 compatible (HW 13) to new UCS servers (ESXi 7, vCenter 8), it was recommended we move all SCSI disk controllers to VMware Paravirtual SCSI Controllers. Three of four deployed Oracle VMs are already there.
Each VM has four SCSI controllers to separate different IO workloads (RHEL file system, ORACLE DATA, Oracle ASM and Oracle REDO). Performance wise it works very well with 'udev' on RHEL 7.9 guest OS and hand off the non RH filesystem drives to DBA who uses Oracle Grid to create required ASM disk groups. The only prep to the VMDKs was adding a 128 block offset using fdisk before handing off to DBA.
Q1. Can I change SCSI controllers from LSI Logic Parallel to VMware ParaVirtual?
Q2. Will changing controller type work without issue on the three controllers that do not have OS data?
Q3. Is there any option to change LSI Logic Parallel controller (SCSI0) if 0:1 is / drive?
NOTE: I did search community. Thanks to those that discussed issues with changing disk controllers if OS boot volume was in place, trouble that LVM has when controller change, and recommendation to change back -- hence Q2 and Q3 above.
Link: https://communities.vmware.com/t5/VMware-vSphere-Discussions/VMWARE-ESXI-6-5-LSI-LOGIC-PARALLEL-SCSI...
One system, which was created first, has four LSI Logic Parallel SCSI Controllers. All others were build as designed with VMware ParaVirtual controllers as part of 12 to 18 percent disk io improvement in Oracle-as-a-VM design
