The motherboard I’m using has the intel c602 chipset. And everything I’ve read and tried has not worked. I am able to use the onboard sata ports but need more. The board has two scsi ports that can be configured as sas/sata passthrough. I have reconfigured the synoinfo.conf Files to add more disks in the operating system. I was able to get the port to work with one drive attatched and as soon as I plugged another drive in they system rebooted. And continued to reboot. I have tested all the hard drives with the onboard sata ports and none of the drives themselves are bad.
Im actually thinking of just disabling the onboard scsi ports and picking up an LSI 9207 SAS controller. I have seen video of that card being installed and working with the standard files.