It’s strange, but when I use my Umbrel node to mine Bitcoin by renting hashrate, using the following, my Umbrel hangs and I have to restart Bitcoin Knots to get it to sync again.
This indicates there was a write error to the drive. It could be the drive beginning to fail, or could be a power issue. Has this happened multiple times, or just once?
My best guess is that high rented hashrate (which causes frequent template/share/RPC/logging activity) naturally increases the CPU, memory, network, and disk pressure on the system. That pressure is likely exposing an unstable power supply, disk, SATA cable/adapter, or filesystem corruption. Obviously that is a long list of possible causes, but unfortunately corrupted data can be caused by many things. The increased pressure on the system is likely bringing whatever that cause is up to the surface.
Probably a good starting point will be checking the disk for errors. For that, SSH into your Umbrel and try running the following:
sudo apt update
sudo apt install smartmontools
sudo smartctl -a /dev/sda
sudo smartctl -t long /dev/sda
Then after the long test completes:
sudo smartctl -a /dev/sda
Bad signs would include reallocated sectors, pending sectors, uncorrectable errors, UDMA CRC errors, media wearout, failed self-tests, or increasing error counters. You’ll kind of need to dig through the report output to see if anything stands out. SMART is a good tool to use for suspected disk failure (one possible cause for what you are seeing).