https://blog.csdn.net/gongyf1977/article/details/84029351
Virtual machine installed a CentOS system, but the system time and real serious discrepancies, may shut down after bios clock is not the reason to go.
Fortunately, the virtual machine can also be networked, you can use the ntp service network clock synchronization.
Switch to root under installation ntpdate
#yum install -y ntpdate
run
#ntpdate time.nist.gov
It has been reported
no server suitable for synchronization found
Error, check online for a long time have not been resolved, and later found out that the machine ntpd service need to turn to sync
Enable local service ntpd
#service ntpd start
We need to wait a few minutes to sync on
If you want to view the synchronization process with ntptrace, also you need to install ntp-perl
#yun install -y ntp-perl
#ntptrace
After a review of time synchronization
#date
It has been updated for the network time, ntp's profile
/etc/ntp.conf
You can not modify
Now just sync the system time, the system also need to time to update the BIOS
#hwclock -w
View BIOS time
#hwclock
It has also been updated, ok