For a little while now, my thinkpad randomly has the following issue while running Debian 10.8 and I have no useful resources online as to how to resolve it. I am running it on a Thinkpad T480
Usually a message about an I/O error means there is a problem with the drive. While it is possible that problem is a firmware problem, cable problem, or a problem with power, usually it means the drive is dying.
You can boot off a live CD and run
smartctl -t short /dev/sda (package
smartmontools if it's not already installed) and then, once the test is done, run
smartctl -l selftest to see the results. Usually this will provide you with an overall summary of the state of the drive, but if not, you can run
smartctl -x to see that.
In my case, it says this:
SMART overall-health self-assessment test result: PASSED
which means my drive is in a good state. I suspect yours will not say that, and you will need to replace your drive. There is no way to effectively repair a broken drive without specialized equipment, so replacement is it.
If the drive reports that it's good, you could then look into things like changing out the cable or querying the power supply via
/proc to see if those are the cause of the problem. But, in my experience, those are less common than drive mortality.