Linux: Time synchronization

Time synchronization

• Setup of hardware Time

hwclock Clock Clock and hwclock usage similar, only one on the line, but clock command in addition to support the x86 hardware system, but also support the Alpha hardware system.

Viewing hardware time

---R

• Synchronization of system time and hardware time

Synchronize system time and hardware time, you can use the Hwclock command.

Modify hardware time on a system-time basis

Hwclock--systohc<==-w

Modify the system time based on the hardware time

Hwclock---

• Update time from a time server with Ntpdate

If your Linux system doesn't ntpdate this command at all,

Yum Install

After the installation, you do not have to do any configuration, and do not need to test directly

 Time . nist.gov    A £ ºntpdate[5014time207.200.  81.113 Offset-0.018788 sec  

If you go out above the description, the synchronization was successful. Then add the following to the/etc/crontab.

# Example of job Definition: #.----------------Minute (0- -)  # | .-------------Hour (0- at)  # |  | .----------Day of Month (1- to)  # |  |  | .-------Month (1- A) OR jan,feb,mar,apr ... #|  |  |  | .----Day of Week (0-6) (sunday=0Or7) OR Sun,mon,tue,wed,thu,fri,sat #|  |  |  | |  # * * * * * * user-name Command to be executed*/ 5 *   * * * ntpdate time . nist.gov #域名或IP synchronized every 10 minutes. 

Linux: Time synchronization