Q: Should I install “Embedded” or “Full” platform if I want to run XigmaNAS from hard-disk?
A: Unless you have VERY SPECIAL needs, or a love of pain, you SHOULD NOT use a full install. Installing Embedded to SSD/USB/Flash work just fine and will prevent frustration from things “randomly” breaking.
Long answer: Periodically, the strengths and weaknesses of Full installs VS Embedded installs are debated.
If you want to run XigmaNAS from a hard-disk it is probably because you want to customize, modify, add plug-ins and/or packages to the OS. None of these are good reasons to choose Full over Embedded. If your system does not support/boot from other devices, or you are very memory constrained (512Mb ram or less), then maybe a Full install makes some sense. The Full platform installed onto a hard drive saves (some tiny bit of) RAM. A Full install will also provide flexibility and ease for OS customization. THIS IS NOT AN ASSET. The Full platform reads and writes to the physical device it is installed on while the system is running. This is also a liability, not an asset. The Embedded platform decompresses the OS into RAM and runs from there. It is designed for purposes; to be installed on CF cards, USB Flash drives, etc., but also runs great when installed to HDD. Embedded is also intended to be resistant to (intentional or accidental) tampering. It saves space and energy when installed to USB/Flash/SSD (non-platter based) media (freeing up hard drives to be used exclusively for storage), but is hard to customize/modify with plug-ins and or packages. This is a good thing. If something goes amiss, reboot, and you're back to a freshly decompressed copy of the OS image. Embedded uses a portion of your RAM equal in size to the OS (about 500Mb). The Embedded platform does all reads and writes in RAM and not the boot device while the system is running thereby lengthening the useful life of CF/other solid state media. The only writes to the boot media are done on firmware upgrade and when changes are made to the configuration. Because Embedded runs in ram, it also runs faster than if it is bound to a hard drive, which may or may not have additional load, slowing the OS down.
To sum up, there are very few reasons to use a Full install, and lots of reasons to use Embedded.