Fix “device excluded by a filter” LVM error.
Install Nexus Repository Manager (NXRM) 3.
Use templates inside shell scripts by substituting environment variables.
I have already described how to strace PHP-FPM processes, but you can also display a strace summary to get detailed information about count time, calls, and errors for each syscall.
Monitor file system events to restart service on every configuration change.
numfmt command-line utility which is a part of the standard GNU Core Utilities to pretty print decimal or binary numbers.
varnishlog to log specific Varnish requests.
Varnish Shared memory Log can put a major strain on the disk (I/O write operations). The solution is to store it on the virtual memory filesystem.
needrestart utility to determine which services need to be restarted after the upgrade.