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Making NTP Work on Hardware with Large Clock Drift

Posted on 2010-04-04 by Curt Sampson :: comments enabled

On some hardware, the system the clock speed is somewhat different from what the hardware claims. This will cause the kernel’s idea of the current time to drift from the actual time, since the actual amount of time that elapses each kernel tick is different from what the kernel thinks (which is typically 10,000 microseconds by default).

If this drift is large enough, ntpd will unable to keep the system time synchronized with the servers to which it is talking. What you’ll typically see in this situation is that ntpdc -p will show no servers with an asterisk next to the name (indicating it’s not synchronizing to any of them) and you’ll see the offsets creeping higher and higher in magnitude.


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Cloning an Encrypted Ubuntu System

Posted on 2010-02-27 by Curt Sampson :: comments enabled

Hey, it’s the one year anniversary of the Starling Software Sysadmin blog! I’m celebrating, but I’m also working. Why? Because I can see that, if I’m going to continue on at the astounding rate of two posts per year, I really need to get one out in the next few months. So why not now?

Today we’re going to talk about doing all sorts of twiddly things that the Ubuntu (or probably Debian, too) installer usually does for you. And, for those of you who read the title of this blog and are already thinking, “It’s simple! Just use dd or Ghost!” we’ll also spend a few minutes talking about why we don’t do that.


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