Are you talking about making the PCIe device (H310 SAS PERC in this case) a pass-through device in VMware, or changing the PERC from a raid controller to an HBA (non-raid)? If you set a PCIe device as a pass-through device for VMware, VMware can no longer use it (including as boot device), so you'd need to boot off of something different (e.g. Dell's Internal Dual SD Module).
Hi, Seems many have had issues with DELL raid controllers disappearing from ESXi - hopefully  this may help others with the same issue. I have a DELL R530 configured with 1 x 2.4Tb RAID5 (raid mode) on a H330 Mini PERC. A vanilla ESXi 6.5a is installed is on the RAID array (no flash or SD storage). I enabled passthrough on the H330 mini PERC and when the server eventually rebooted, the controller disappeared (along with the vmfs storage volumes). The H330 was still shown in the hardware list with the passthrough enabled (which would not stay disabled when I tried to change back). I could not do any config changes to the ESXi through ESCLi (could not be live updated errors) When I eventually got physical access to the server, I performed te following steps: - Upgraded to ESXi 6.5 u1 DELL custom image. RESULT: No change, no controller / storage found. - BIOS was a little old, so updated all onboard R530 BIOS / FW to latest versions. RESULT: Still no change. - Decided to install ESXi on USB flash drive (as recommended - don't have SD storage installed). RESULT: storage found and remounted VMs and happy days.   I think I know the cause. On the new ESXi install, the H330 PERC mini passthrough is disabled. On the old ESXi install, I had enabled H330 passthrough and I could not disable H330 passthrough.   I would like to monitor the RAID array from the VMs, but I'm now paranoid of enabling passthrough as the ESXi VMs were offline for almost a week.  I would really like to know if anyone has experienced issues after enabling H330 (or others) passthrough in ESXi 6.5.
ESXi 6.5 on R530 H330 no storage after passthrough enabled