Why a PCIe SATA Drive Can Appear in ZimaOS but Not in BIOS
The thread describes drives attached through a PCIe-to-SATA controller that were visible after the OS loaded but unavailable as firmware boot targets. That distinction matters: operating-system detection only proves the kernel has a driver for the controller; booting also requires the system firmware and controller option ROM/UEFI path to expose a bootable device.
Review the current ZimaOS installation guide before changing boot media, and use the ZimaOS storage setup guide after the system boots.
Community Troubleshooting Checklist
An IceWhale reply reported successful TrueNAS booting from a SATA drive connected through a PCIe-to-SATA card and recommended checking whether installation used UEFI or legacy mode, using an official OS image, and testing a clean installation without competing systems. This confirms one tested configuration, not universal compatibility with every controller.
Check the Controller Before Reinstalling
Identify the PCIe SATA controller chipset and confirm that it supports booting rather than only post-boot storage. UEFI's overview of firmware boot architecture is available from the UEFI specifications, while the Linux kernel's driver documentation helps explain why a device can work after the kernel starts even when firmware cannot boot from it.
When to Use a Separate Boot Device
If firmware never exposes the controller's disks as boot targets, a practical architecture is to keep the OS on a firmware-visible SATA, NVMe, eMMC, or supported boot device and use the PCIe SATA card for data disks. For hardware planning, see the ZimaBlade 2 product page.
