Disk full at 3am: finding it fast
A sequence that finds the cause in about a minute, including the case where df and du disagree.
Writing
linux
Understanding load average
It is not a percentage, and a load of 8 may be perfectly healthy.
SSH hardening without locking yourself out
The order of operations matters more than the settings.
Log rotation that does not lose data
The default rotation method silently breaks with any process that holds its log open.
systemd Type=simple versus Type=forking
Get this wrong and the service either restarts forever or is reported dead while running.