topic Re: Real-Time Clock in Operating System - HP-UX

Real-Time Clock

sonya goddard — Thu, 24 Jan 2002 15:26:24 GMT

What is the function of the Real-Time Clock? What is its purpose? Does it stamp the date on files or does the System Clock stamp the date on files. Thanks in advance

Re: Real-Time Clock

Steven Sim Kok Leong — Thu, 24 Jan 2002 15:32:39 GMT

Hi,

Reminds me of Y2K bug.

Extracted for your interest:
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The RTC (also known as the Time-of-Day Clock) is responsible for maintaining the time of day at all times. This includes when the operating system is not running as well as when the power is turned off. The System Clock is responsible for maintaining the time of day for the operating system while the system is running. The hardware of the System Clock is the interval time, which is used in conjunction with software data structures and procedures to compute system time.

HP realized that problems may occur in interactions between Processor-Dependent Code (PDC) and the RTC, and in the RTC hardware itself. The RTC was run through the year 2000 testing to verify that it returns to a proper value after rolling past the year 2000. The tests also dealt with Universal Time Coordinated (UTC) - which replaced Greenwich Mean Time (GMT) - to ensure that any two-digit fields in the hardware and associated PDC were checked.
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Hope this helps. Regards.

Steven Sim Kok Leong

Re: Real-Time Clock

Steven Sim Kok Leong — Thu, 24 Jan 2002 15:37:44 GMT

Hi,

To answer your question, based on above information, the files are stamped with the system time which is derived from the System Clock.

Hope this helps. Regards.

Steven Sim Kok Leong

Re: Real-Time Clock

sonya goddard — Thu, 24 Jan 2002 15:47:30 GMT

Thanks for your help. I have one more question. When we tried to set the RTC, we got an error of -3. Do you know what this means? We had input the correct time and in the correct format. When we just typed DATE, it gave us an error code of -13.

Thanks for your time.

Re: Real-Time Clock

melvyn burnard — Thu, 24 Jan 2002 16:20:36 GMT

You do not say whch model 9000 system this is on, nor the OS version. This may help.
Some systems do not allow changing of the RTC.
You could also have a hardware problem

Re: Real-Time Clock

Helen French — Thu, 24 Jan 2002 16:36:02 GMT

Hi,

If you have L or N class server, it is not possible to change the server's RTC. The RTC is set to GMT from the factory itself, and the kernel synchronizes to what it reads from this clock during the system boot.

If that is not the case, then try changing your date and time using 'date -u' command. See man pages of date

HTH,
Shiju