[TriLUG] System question

[Aaron S. Joyner]

Jason wrote:

>use ntpdate to set the date from a ntp server
>
>i.e. ntpdate  pool.ntp.org 
>
>Jason
>
>On Sat, Apr 29, 2006 at 03:59:02PM -0400, WA Brown 
>wrote:
>  
>
>>How can I change the system time while I am on ssh? I want to check the 
>>system time on the server and maybe change it. How can I do it remotely 
>>with ssh? I have an :
>>
>>Redhat 9
>>Apache 2.0 server
>>
>>
>>WA Brown 
>>
>>
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>>    
>>
>
>  
>
Since you seem to quesiton how to do it remotely, and you probably want 
it to stick across reboots, I suspect you're really more intersted in 
ensuring the hardware clock on the motherboard is corrected.  You should 
read the man page for `hwclock`, after which you will probably feel 
compelled to run `hwclock --systohc`.  Since you probably don't want to 
do this on a regular basis, and it sounds like the machine has internet 
access at least some of the time, you should probably see about running 
ntpd, the Network Time Protocol Daemon, which will keep the current 
clock in sync w/ the real time according to the outside world.  You 
should also check to see that your distribution runs hwclock --systohc 
on shutdown and reboot (as most any modern distro probably does).  You 
may also wish to cron up this task, say perhaps once every day or wo, 
such that when your system reboots it's sure to have a reasonably-sane 
time before ntpd gets started and sets it to an accurate time.

Aaron S. Joyner

PS - As a side note to interested parties who go may read the hwclock 
man page, don't use hwclock --adjust and ntpd together, as the drift 
file ends up thinking the hwclock is perfect, which ruins the usefulness 
of --adjust.  ntpd is of course the preferable and more acurate way to 
maintain the clock over a long period of time, hwclock --adjust is most 
useful for those who don't have the luxury of internet access all the time.