Help me about time error

[carroty]

$ cat test.sh
echo `date +'%Y%m%d %T'` " c start"
echo `date +'%Y%m%d %T'` " c done "

I run the script above for many time and got the wired error for linux time:

$ sh test.sh
20090510 15:58:23 c start
20090510 15:58:23 c done
$ sh test.sh
20090510 15:58:30 c start
20090510 15:58:30 c done
$ sh test.sh
20090510 15:58:30 c start
20090510 15:58:30 c done
$ sh test.sh
20090510 15:58:31 c start
20090510 15:58:31 c done
$ sh test.sh
20090510 15:58:31 c start
20090510 15:58:31 c done
$ sh test.sh
20090510 15:58:32 c start
20090510 15:58:32 c done
$ sh test.sh
20090510 15:58:33 c start
20090510 15:58:33 c done
$ sh test.sh
20090510 15:58:33 c start
20090510 15:58:33 c done
$ sh test.sh
20090510 17:11:52 c start <-------------see this
20090510 15:58:34 c done


If I repeatedly run "date" it will get the same error, and this error seems to be happen randomly without any pattern to analysis.

Any one can help me about this ? thank alot~

[carroty]

date version

date (GNU coreutils) 5.97
Copyright (C) 2006 Free Software Foundation, Inc.

[Rubberman]

Neat! You've discovered time travel!
Really, I've never seen this. My date is the same version as yours.
Ok. I made the same test.sh that you show and tried it a LOT of times. No problems here. Maybe it is a hardware problem? Or an ntp problem? Don't know, but as I said, I cannot reproduce it on my system - Intel S5000XVN mb, dual E5450 xeon processors, 8GB RAM, running CentOS 5.3 with latest kernel, updated yesterday.

[carroty]

Neat! You've discovered time travel!
Really, I've never seen this. My date is the same version as yours.
Ok. I made the same test.sh that you show and tried it a LOT of times. No problems here. Maybe it is a hardware problem? Or an ntp problem? Don't know, but as I said, I cannot reproduce it on my system - Intel S5000XVN mb, dual E5450 xeon processors, 8GB RAM, running CentOS 5.3 with latest kernel, updated yesterday.

thanks for ur help, Maybe it is the linux configuration that lead to this situation.

I have runed the script on other linux , it doesn't error. I am confussed , but thanks for ur help~

[Rubberman]

thanks for ur help, Maybe it is the linux configuration that lead to this situation.
I have runed the script on other linux , it doesn't error. I am confussed , but thanks for ur help~

As I suggested, this could simply be a glitch in the real-time clock of the system that exhibits this behavior. I would also suggest that you run extended diagnostics on the system to see if there is a problem with the motherboard and clock.

Re. your comment that it doesn't occur on other Linux. Do you mean that it doesn't happen with another version of Linux running on the same computer system? Or that it doesn't happen on another computer system running Linux? The distinction is important.