I did try to check the logs but don't know what to look for. Disk is almost full, it's 1TB so even with minimal apps I'm 50-60GB to be full. However issues happened for some times now, before I was above 900GB, even if it stopped a couple of months before starting over again more or less regularly.
CPU and RAM are never at 100% when I check.
When the crash or freeze occur, try to look into the logs, maybe there is some clues about any issue.
Disk is a whole world, so I was talking to check not only the space, S.M.A.R.T, which stands for Self-Monitoring, Analysis, and Reporting Technology, is a system used to monitor the health of hard drives.
But... if you have a couple of dollars and don't have time, maybe it's time to migrate to a better hardware, some NUC with better performance for the next 2 or 3 years.
Downsize to the minimum that you need to cover your usual user case and focus on analyze that, less process is better to search root causes.
