UEFI from BIOS support change after installation

[alevene]

We've been using FreeNAS for years with excellent reliability. It boots from a USB stick. I just noticed that the BIOS was set to BIOS and not UEFI. I am reluctant to change it if it will potentially damage the NAS. The system is running using 10 3TB drives, that should not be visible as BIOS only supports 2TB, but it does.

Does anyone have any experience changing to UEFI from BIOS in a production system? I doubt that it will harm the array, but I'd like to find out what others have found. Thank you.

 

[wblock]

This is likely just how it boots, whether from an MBR or a UEFI partition setup. MBR is simpler.

FreeNAS does not use the BIOS to access the drives, but speaks directly to them, and so does not have the limitations of the BIOS.

In summary, this setting only changes the boot mode. If there had been a BIOS size limit problem (which does not apply anyway), you would have noticed it when the system was first set up.

No, do not change this setting. You could, and if the boot device was set up to boot in either BIOS mode or UEFI mode, it would still work. If the boot device was not set up to do both, it would not boot at all. Either way, this would not affect data on the drives, just booting. If you changed it and it did not boot, just change it back.