java.io.IOException: Input/output error on Dedicated Server

What the log looks like

java\.io\.IOException: Input/output error
java\.io\.IOError: java\.io\.IOException: Input/output error

How to fix it

1. Check the lines immediately following 'Input/output error' in your log to see whether the crash came from console input (org.jline / SimpleTerminalConsole) or file writes (RandomAccessFile / RegionFile).
2. If the error comes from org.jline or SimpleTerminalConsole over SSH, launch your server inside a terminal multiplexer such as 'tmux' or 'screen' so detaching or losing your SSH connection does not kill the server's terminal.
3. If you run the server via a custom background script or systemd unit without an interactive console, pass '--nojline' at the end of your server arguments (or '-Dterminal.jline=false' in JVM flags) to disable JLine console reading.
4. If the error comes from RandomAccessFile, logs/latest.log, or RegionFile threads, check disk space and kernel storage errors on Linux using 'df -h' and 'dmesg -T | grep -iE "i/o|error|ext4|xfs"', or open a support ticket with your hosting provider about a failing drive.
5. Take an immediate off-machine backup of your world folder if disk I/O errors are occurring, and avoid overwriting the server JAR file while the server process is still running.

Check your own log