Solutions
CentOS 7 yum 404: inspect the failing repository first
Distinguish an archived CentOS mirror from a third-party URL, DNS, TLS or network failure before rewriting repo files.
Does every yum failure need switch-centos7-repo.sh?
2026-10-30
1
Solutions
Problem-first solution pages
Land directly on pages written for common operations questions, not just script filenames.
Solutions
2026-04-07
Why is CentOS 7 SSH login so slow
The usual causes are reverse DNS lookup, GSSAPI auth negotiation, and sometimes IPv6 fallback. Disable those waits before doing deeper SSH troubleshooting.
What should I change first when SSH login on CentOS 7 takes too long before the password prompt appears?
Solutions
2026-04-07
Why can I not connect after disabling SSH password login on CentOS
The usual cause is disabling PasswordAuthentication before confirming that the target account already has a working authorized_keys file and a successful key-based login test.
What is the most common reason a CentOS server becomes unreachable right after disabling SSH password login?
Solutions
2026-10-30
OpenVPN connects but internal DNS fails
Inspect the configured hook and active resolver manager before changing files or restarting the tunnel.
Does an active OpenVPN service prove private names should resolve?
Solutions
2026-10-29
Why MySQL 5.7 keeps old credentials after container replacement
The helper reuses /data/mysql5.7/data when replacing mysql57. MySQL initializes accounts only for an empty data directory, so changing install variables does not reset an existing database.
I supplied a new MYSQL_ROOT_PASSWORD, database, or user on a rerun. Why are the old credentials and data still there?
Solutions
2026-10-30
Workerman says completed but HTTP readiness failed
Separate build, container startup, the optional curl probe and application validation before another replacement.
Does the completion banner prove the application is healthy?