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The Linux hardware clock and system clock (Doc ID 1542502.1)

Last updated on APRIL 21, 2020

Applies to:

Linux OS - Version Oracle Linux 5.0 to Oracle Linux 6.4 [Release OL5 to OL6U4]
Oracle Cloud Infrastructure - Version N/A and later
Linux x86-64
Linux x86


There are two type of clocks in the Linux system - hardware clock and system clock.
This article describes the difference and relationship between them.

Questions and Answers

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In this Document
Questions and Answers
 1: What are the hardware clock and system clock?
 2: Synchronising the hardware clock and system clock
 3: How the hardware clock and system clock are synchronized during system is shutdown

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