Server Management

A menu script is a useful way to practice input, branching and loops in Bash. It is also an easy place to make a destructive mistake if a filename is ...

A successful import message does not establish that the backup contains everything the application needs. The wrong database may have been selected, s...

During an SQL import, ERROR 1062: Duplicate entry means a PRIMARY or UNIQUE key would be violated. It does not necessarily mean the same row appears t...

If a name such as “Çağrı” appears as garbled symbols, do not immediately run ALTER TABLE across the database. The value may have been stored incorrect...

An SQL dump that stops with Unknown collation: 'utf8mb4_0900_ai_ci' is not necessarily damaged. The destination may not recognize the comparison rule ...

You select an SQL backup, start the import, and receive a blank page or timeout several minutes later. Retrying immediately is tempting. However, the ...

An unavailable NFS server can make harmless-looking commands such as df, ls or a monitoring probe block. The first recovery rule is to stop touching t...

Seeing an inbound UDP/161 packet in tcpdump does not prove that the SNMP agent received or accepted it. The host firewall can still drop the packet, s...

Archive scope: The text below records an older manual Ubuntu 22.04 installation; do not copy it for a new deployment. Follow the Ubuntu 24.04 LTS pack...

Databases are critical for ensuring applications run fast and reliably. However, misconfigurations, limited hardware, inefficient queries, missing ind...