[ntp:questions] NTP not syncing

Steve Kostecke kostecke at ntp.org
Sun Nov 10 17:14:18 UTC 2013

On 2013-11-08, Antonio Marcheselli <puppa at me.la> wrote:

> Question related to this topic. I am told that I can enable the HPET on 
> the motherboard and I can tell linux to use it.
> The file I am trying to amend is 
> /sys/devices/system/clocksource/clocksource0/available_clocksource
> I have a I/O error when I try to save. The folder and the file have RW 
> permissions, any idea on why I can't amend it?

Sysfs (/sys/*) is a virtual file system provided by Linux. Sysfs exports
information about devices and drivers from the kernel device model to
user space, and is also used for configuration. It is similar to the
sysctl mechanism found in BSD systems, but implemented as a file system
instead of a separate mechanism.

Sysfs documentation is available at

/sys/devices/system/clocksource/clocksource0/available_clocksource is
the Sysfs interface for listing the available clock sources.

/sys/devices/system/clocksource/clocksource0/current_clocksource is the
Sysfs interface for listing _or_ setting the current clock source.


# cd /sys/devices/system/clocksource/clocksource0/
# ls -l
total 0
-r--r--r-- 1 root root 4096 Jul 18 07:48 available_clocksource
-rw-r--r-- 1 root root 4096 Nov  9 14:28 current_clocksource
# cat available_clocksource 
tsc hpet acpi_pm 
# cat current_clocksource 
# echo hpet > current_clocksource
# cat current_clocksource

Steve Kostecke <kostecke at ntp.org>
NTP Public Services Project - http://support.ntp.org/

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