[mythtv-users] Can't solve a problem with Skipping/Fast Forwarding

[Paul Bender]

chris at cpr.homelinux.net wrote:

> On Wed, Aug 16, 2006 at 08:30:36AM +0100, Stephen Robertson wrote:
> 
>>I think I have checked NTP but to be honest I've not found out how to
>>conclusively check that it is working.
> 
> 
> First of all, are you running ntpd (the full ntp client/server 
> daemon) or ntpdate (the one-shot time correction tool)?
> 
> The ntpdate package is usually installed to run only once at system 
> boot.  If you want to use it to keep your system up to date then 
> you'll need to have a cron job that runs ntpdate every hour or so.
> 
> If you have both ntpdate and ntpd installed then ntpdate won't do 
> anything (it detects ntpd is running and exits without making 
> changes).

MiniMyth has both ntpdate and ntpd. I case the clock is completely 
wrong, it runs ntpdate once to correct the clock. Then it starts the 
ntpd daemon.

> The ntpd daemon normally logs to the syslog facility, which means 
> that its output can be tossed if syslog thinks the messages are 
> unimportant.  You can specify a log file in /etc/ntp.conf and the 
> daemon will tell you what it's doing.

MiniMyth logs NTP to syslog: /var/log/messages.

>>I have configured my DHCP server to provide the details of an NTP
>>server and from my reading of the minimyth documentation it should
>>bomb out with an error if there is a problem with it.
> 
> 
> What should bomb out?  The DHCP server?  The DHCP client?  The 
> ntpd/ntpdate program?  Myth?

The init scripts for MiniMyth check to make sure that at least one NTP 
server was provided by DHCP (or by the parameter MM_DHCP_NTP_SERVERS). 
If not, it prints an error message to the boot splash screen and to 
syslog and exits. This is done to make sure that people provide an NTP 
server.

However, it does not check to make sure that the NTP server is working 
correctly. To check this, as was suggested above, look in the syslog 
file: /var/log/messages. If it is working correctly, then there should 
be an ntpd message containing the phrase 'synchronized to' followed by 
the NTP server address and the stratum.

> Are you sure that the DHCP client on your myth box is even capable 
> of reading the ntp information from the lease?  You could (and 
> probably should) consider bypassing any DHCP and local ntp server 
> issues by specifying a time server in the ntp config file and 
> allowing it to reach out to a known-good server on the internet.  
> You can worry about peering to your local network later once you've 
> got a client that is known to be working.

The client is capable of reading the ntp-servers from DHCP. The client 
is the udhcpc client that comes with busybox but patched to enable 
requesting ntp-servers from the DHCP server. The script used by udhcpc 
puts the received ntp-servers into /etc/ntp.conf preceeding each one 
with the key word 'server'.

Therefore, if everything worked correctly, then the ntp-servers should 
be /etc/ntp.conf, which can be checked by telnetting into the MiniMyth 
frontend and running 'cat /etc/ntp.conf'

In order to override the ntp-servers provided by the DHCP server, one 
can put MM_DHCP_NTP_SERVERS=<ntp-servers> on the boot command line.