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My laptop's clock (Acer Extensa 5220) seems to be slow. I've corrected it 5 minutes forward last week and now have just corrected minute forward again.

How it's better to fix it? Is there a program [apart from time servers] to correct clock properly, for example, by shifting it a bit every hour?

Is there already a program to put it to crontab or I should hack up a script? Or I should check more things?

Update: I have found that HW clock is right, but system time is slow: about a second each 2.1 hours.

root@vi-notebook:~# dmesg | egrep 'clock|unstable'
[    0.103785] Switching to clocksource tsc
[    0.265274] Marking TSC unstable due to TSC halts in idle
[    0.265514] Switching to clocksource acpi_pm
[    1.321408] rtc_cmos 00:09: setting system clock to 2010-10-30 00:10:48 UTC (1288397448)

Is placing "hwlock --hctosys" to crontab a right thing?

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Have you checked to see if your hardware clock is the same as your system's clock? –  ricbax Oct 20 '10 at 2:40
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Curious, why no time servers? –  Rich Homolka Oct 20 '10 at 4:12
    
Because I want the clock to be OK even if no internet connection. (Actually I may be just really set up time server connection). –  Vi. Oct 20 '10 at 10:30
    
NTP is still your answer. It'll also ensure that when you have no Internet connection your clock is kept relatively accurate. –  Cry Havok Oct 20 '10 at 10:46
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3 Answers

This is the wrong solution. Investigate the clock, clocksource, notsc, and tsc kernel parameters.

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You could install and setup the NTP time sync to resync the clock if/when you have an Internet connection. There's lots of guides on 'teh 'net', but I have picked this one

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Try installing NTP, that should (if the drift isn't too high) keep your clock in sync. Once it's got your clock in sync it'll track the drift against what it should be and when you aren't Internet connected your clock will still be about right.

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