I live in an area where brown outs happen often (sometimes a few times per week). I had QubesOS installed on a computer and it was working fine but after one of these brown outs the whole OS corrupted and it refused to boot.
Is there any way to prevent this from happening besides getting a UPS? Perhaps disable write caching?
Well getting a laptop with Qubes OS on it is one solution.
I was hoping for something i could do to the operating system itself. I currently use Mint Linux and that never corrupts, even after brown out. But i want to move away from it because Qubes is more secure.
Qubes OS is not more secure against brown outs apparently, based on your experiences.
I see this issue as clear cut. Your issue is about power reliability, which is a hardware issue, so hardware solutions are more appropriate for it. This is not about Qubes OS suddenly shutting off on its own regardless of power source used.
Get a UPS, a laptop, or even a power generator to handle external variables out of your control.
Try btrfs + file-reflink or some other file system you trust.