Reasonably expert, long-time user of the home edition of Sophos XG and (before that) Sophos UTM. It has been ages since I performed a full install … and this weekend I learned A LOT about things that can go wrong AND how to resolve them.
Motherboard is a contemporary Gigabyte H370N, a nice rugged choice with the bonus of a usable i211 Ethernet (the second Ethernet is an unusable i219, common to most motherboards). Additional i350 Ethernet (one, two, or four ports) on a PCIe card.
Issue #1: cannot boot installer from USB drive
Resolution: Enable CSM Support AND set Storage Boot Option Control to Legacy. Default settings assume you want to run UEFI only--a reasonable assumption in 2020--but the Sophos installer is strictly MBR/BIOS.
Issue #2: still cannot boot installer from USB drive
Resolution: use a USB 2 drive OR an CD-ROM drive. USB 3 is not natively supported and requires driver support from the installer--a reasonable assumption in 2020--but the Sophos installer lacks this support.
Issue #3: installer starts (YAY) and quickly stops (BOO) with "Unable to Detect Primary Disk"
Resolution: use a SATA SSD drive. M.2 NVMe is one of the most wonderful PC developments in ages: fast, reliable, affordable, and zero added footprint. But the Sophos installer is not NVMe compatible, full stop. SATA SSDs work like a charm AND that includes M.2 SATA drives. The latter are two years old, becoming harder to find, and cost slightly more than their NVMe counterparts … but they WORK and at this point the mission is all about mitigating frustration.
Summary: contemporary PC hardware with default settings can be a migraine
Awful lot of Google searches PLUS trail-and-error outlined above. I hope this saves other folks time and angst in the future! If you've encountered installation issues AND resolved them, please append to this thread for the good of mankind.
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