• How to create systemd service unit in Linux
• Set systemd service to execute after fstab mount
• DigitalOcean Tutorials systemd:
  • How To Use Systemctl to Manage Systemd Services and Units
  • Understanding Systemd Units and Unit Files
  • How To Use Journalctl to View and Manipulate Systemd Logs
  • Systemd Essentials: Working with Services, Units, and the Journal
• NFS mount via systemd
• How to start systemd service after NFS mount in Linux

systemd-analyze – Find System Boot-up Performance Statistics in Linux

man journald.conf manual page for journald.conf
man journalctl manual page for journalctl

Edit sudo vim /etc/systemd/journald.conf make variable Storage=persistent to make journald store the journal files in /var/log/journal, this will create directory if necessary. This also ensure log files are available from previous boots.

sudo systemctl force-reload systemd-journald to reload journald or restart instead sudo journalctl -u systemd-journald to check status of journal.

some useful flag and inputs:

• sudo journalctl -b to see current boot journal only use -b -1 to see last boot entries.
• journalctl –list-boots to list all available journaled boots.
• sudo journalctl -u pppoe, use u flag to see specified unit files only.
• sudo journalctl -k to see kernel messages only
• sudo journalctl -p 3 to see only specified error priority messages and more severe.
  • 0: emerg
  • 1: alert
  • 2: crit
  • 3: err
  • 4: warning
  • 5: notice
  • 6: info
  • 7: debug
• -r flag is used to show in reverse chronological order.

some links:
Use journalctl to View Your System's Logs

timedatectl to print current time date on cli
Date to print basic time date only on cli
timedatectl list-timezones to set available time zones
sudo timedatectl set-timezone australia/perth to set timezone

Some links:

• Arch Linux systemd/Timers
• Putorius Using systemd Timer Units to Schedule Jobs
• Linux.com Systemd Timers: Three Use Cases

• Freedesktop.org systemd.time — Time and date specifications and systemd.timer — Timer unit configuration