simple script based fake-hwclock for systemd systems
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LICENSE
README.md
install
soft-hwclock
soft-hwclock-tick.service
soft-hwclock-tick.timer
soft-hwclock.service

README.md

soft-hwclock

description

Many simple systems, such as the Raspberry PI, don't have hardware clocks. When they boot, they start with their system clock set at some fixed date, e.g. 2000/01/01 00:00:00.

A soft hwclock sets the initial time to some known value from before the last reboot. This brings the clock into a sensible range prior to getting a better value from network based services such as ntp. Should the network not be available, services can continue to run from where they left off, avoiding problems with an internal clock set far in the past conflicting with recent timestamps.

Some systems have packages to do womething similar, while others don't. This repository consists of shell scripts and service files for systemd based systems to achieve this, and has been tested on a Raspberry Pi 3 running CentOS 7

features

Sets the time to a "recent" timestamp early in the boot to avoid timestamps far in the past when booting, prior to getting a proper timestamp from the network.

  • Restores the system clock from file during early boot
  • Saves the clock into a file at shutdown
  • Regularly saves the current time into the data file, in case of improper shutdown.
  • shell based to avoid platform and binary dependencies.
  • contains soft-hwclock.service and soft-hwclock.timer systemd units.

installation:

  1. copy these files into an empty folder, e.g. myfolder.
  2. install the services: cd myfolder; chmod +x install; ./install This will install it into /opt/soft-hwclock, and the unit files into /etc/systemd/system.
  3. The install script has enabled and started the service, but you can also do it manually: systemctl enable soft-hwclock.service && systemctl start soft-hwclock.service

See also:

This package is inspired by Steve McIntyre's fake-hwclock package for Debian.