Hello,

Unraid was shutdown for no reason, how I find hy? The logs only shows whatever happened when it boots.

The syslog in the diagnostics is the RAM version that starts afresh every time the system is booted. You should enable the syslog server (probably with the option to Mirror to Flash set) to get a syslog that survives a reboot so we can see what leads up to the problem. The mirror to flash option is the easiest to set up (and if used the file is then automatically included in any diagnostics), but if you are worried about excessive wear on the flash drive you can put your server's address into the remote server field and log to a share instead.