Troubleshooting: PostgreSQL pg_log Disk Space Exhaustion & Database Lockfile Issues on Ubuntu 20.04 LTS
Resolve critical PostgreSQL database outages caused by pg_log disk space exhaustion leading to lockfile errors on Ubuntu 20.04 LTS servers.
Tag Directory
#sysadmin Solutions
Browse all server troubleshooting guides and configuration walkthroughs tagged with #sysadmin.
Git Error: ‘rejected non-fast-forward’ Push Conflicts on CentOS Stream / Rocky Linux
Resolve Git 'rejected non-fast-forward' errors on CentOS Stream & Rocky Linux. Understand push conflicts, rebase, merge, and force push strategies for clean Git workflows.
Fixing Apache “Client denied by server configuration” 403 Forbidden Errors (Ubuntu, Alpine, WSL2)
Comprehensive troubleshooting guide for AH01630: client denied by server configuration. Learn root causes, system traces, and verified resolutions.
Fixing Caddy Reverse Proxy TLS Handshake & Certificate Verification Errors
Comprehensive troubleshooting guide for tls: failed to verify certificate: x509: certificate signed by unknown authority. Learn root causes, system traces, and verified resolutions.
Resolving “Port is Already Allocated: bind failed” in Docker Compose (Debian, Ubuntu, macOS, WSL2)
Comprehensive troubleshooting guide for bind: address already in use. Learn root causes, system traces, and verified resolutions.
Fixing Let’s Encrypt & Certbot Verification Failures (HTTP-01 / DNS-01 Challenges)
Comprehensive troubleshooting guide for Certbot failed to authenticate some domains (HTTP-01 / 403 Forbidden). Learn root causes, system traces, and verified resolutions.
Resolving MySQL / MariaDB Error 1040: “Too many connections” & System Limit Tuning
Comprehensive troubleshooting guide for ERROR 1040 (HY000): Too many connections. Learn root causes, system traces, and verified resolutions.
Fixing Nginx 502 Bad Gateway with PHP-FPM Unix Socket & TCP Pools (Ubuntu, Debian, Alpine, WSL2)
Comprehensive troubleshooting guide for connect() to unix:/var/run/php/php-fpm.sock failed (111: Connection refused). Learn root causes, system traces, and verified resolutions.
Troubleshooting Nginx 504 Gateway Timeout: Upstream Timeouts & FastCGI Buffer Tuning
Comprehensive troubleshooting guide for upstream timed out (110: Connection timed out). Learn root causes, system traces, and verified resolutions.
PostgreSQL Shared Buffers & Memory Limits: Resolving Crash on Startup (Ubuntu, Debian, Rocky Linux)
Comprehensive troubleshooting guide for could not create shared memory segment: Invalid argument. Learn root causes, system traces, and verified resolutions.