Tag: system administration

As you may know, there are two kinds of email systems: Outlook, and everything else. The non-Outlook-based email world consists mainly of three kinds of software: MDAs, MUAs, and anti-spam/antivirus. Dovecot is the glue between your MDA and your MUA.[gview file=”https://blog.learningtree.com/wp-content/uploads/pdf/dovecot-email-flow.pdf”] MDAs are the mail delivery agents, such as SendMail, PostFix, OpenSMTPD, and more. An […]

A consulting client had asked for my help in a Solaris-to-Linux migration, and we had the big moves done. We were cleaning up, doing “while you’re here” tasks, just checking to verify that some things were working as expected. The backup process had moved to Linux about a year ago, and migrating web service of […]

Cybersecurity laws and other regulations clearly exist for good reasons, and there are serious penalties involved if you fail to meet them. The new version of PCI DSS, the Payment Card Industry Data Security Standard, requires going beyond showing that data can be secure, you must show that it will be secure through established procedures […]

Last week I showed you how to determine your current run state and figure out what that really means. Let’s control some services to tune the state of our system! The systemctl command is the master tool for controlling and querying the systemd system and service manager. Both it and the related journalctl command truncate […]

The change from classic init to systemd is a really big one. Some may even say controversial! A few old standbys still work — for now — as automatic workarounds. We can still do major state changes with reboot, halt, and poweroff; by running init with a numerical argument, and with shutdown. Also, Red Hat’s […]