文章

 Command Not Found

Fix: Package not installed? `apt install name`. Or check $PATH.

 Cron Not Running

Fix: `systemctl status cron`. Check syntax of crontab.

 DNS Resolution Failure

Fix: Update `/etc/resolv.conf`. Add `nameserver 8.8.8.8`.

 Destination Host Unreachable

Fix: Network issue. Check `ip a`. Check gateway.

 Fail2Ban Banned Me

Fix: Wait ban time. Or restart fail2ban via VNC to clear jams.

 Firewall Lockout

Fix: Use VNC Console. Run `ufw disable` or `systemctl stop firewalld`.

 High Load Average

Fix: Run `htop`. Identify process. Kill if stuck.

 Host Key Verification Failed

Fix: Server Re-imaged? Run `ssh-keygen -R [IP]` to clear old key.

 Kernel Panic

Fix: Corrupt update? Boot into previous kernel via Grub. Or Rescue Mode.

 MySQL Crash loop

Fix: Check error log. Likely OOM. Add swap space.

 No Space Left on Device

Fix: `du -sh /*`. Clear logs: `journalctl --vacuum-time=1d`.

 OOM Killer (Out of Memory)

Fix: MySQL crashing? Add Swap space. Upgrade RAM.

 Package Manager Locked

Fix: `rm /var/lib/dpkg/lock-frontend`. Kill apt process.

 Read-only filesystem

Fix: Filesystem corruption. Reboot for fsck check. Contact Support.

 SSH Connection Refused

Fix: Server might be OFF. Firewall might be blocking Port 22. Check VNC.

 SSH Permission Denied

Fix: Root login disabled? Use Key? Wrong password?

 Systemd Service Fail

Fix: `systemctl status name`. `journalctl -xe` for details.

 Time Sync Fail

Fix: Install NTP. `timedatectl set-ntp on`.

 Too Many Open Files

Fix: Check `ulimit -n`. Increase limits in `/etc/security/limits.conf`.

 Web 403 Forbidden

Fix: Webroot owner must be user/www-data. `chown -R www-data:www-data /var/www`.