OT: clock drift (was: Re: logging postfix and others)

[Scott Haneda]

On Mar 2, 2009, at 3:21 AM, Ryan Schmidt wrote:
> On Mar 1, 2009, at 03:37, Scott Haneda wrote:
>
>> First thing I do in setting up a new server is comment out the log  
>> rollers, second is set up a ntpudpate command in launchd to keep  
>> the clock from drifting.
>
> I realize this is off-topic now, but you've made me curious. Can the  
> clock drift if you do not do this? I thought Apple's "set date and  
> time automatically" option was supposed to ensure clocks were  
> synchronized. Though I admit I don't know what it does specifically.


I see the clock drift massively on my servers, it seems to be the  
worst when you are using a server that does not login to an account,  
then apples "set data and time automatically" does not seem to work  
well.

This drift is a killer when you are trying to figure something out in  
logs that spam multiple machines.

I will add this launchd item:
( Sleep 45 seconds to wait for the network to come up, adjust  
accordingly, ugly hack, but works )

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd 
">
<plist version="1.0">
<dict>
	<key>KeepAlive</key>
	<true/>
	<key>Label</key>
	<string>com.hostwizard.ntpdate</string>
	<key>ProgramArguments</key>
	<array>
		<string>/bin/sleep</string>
		<string>45;</string>
		<string>/usr/sbin/ntpdate</string>
	</array>
	<key>RunAtLoad</key>
	<true/>
	<key>StartInterval</key>
	<integer>300</integer>
</dict>
</plist>


--
Scott

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