What is a “Step Ticker”
You know, it’s one of those little pedometer things you strap onto your hip and tracks how far you’ve walked. Ok, so it’s not that. At least not within the context of servers & virtualization. So what IS it? It’s a horribly named NTP (network time protocol) concept. Yup. That’s it. You were expecting at least two other paragraphs, no?
What does it do?
Hate to disappoint, this paragraph is going to be short too. A Step Ticker is basically a way to tell the NTP daemon to check a server or two, and correct time on startup, rather than relying on the time that was restored from the hardware.
This is meaningful, because often the hardware time has drifted. If you are running applications that are exceedingly time sensitive, like virtualization, you’ll of course want accurate time. So setting up Step Tickers is a “Good Idea”. So how do we do that?
Setting Up Step Tickers
I’ll show you how to do this on a single host, as well, that’s easy, and I’m lazy. To deploy in mass, you’ll likely want this as part of your kickstart process. If you don’t have automated builds, shame on you, but you should have it as part of your QC process then. As for scripting the change out to each host, that is best left to you, the reader (but can be done in PoSH with plink).
Enough rambling, open /etc/ntp/step-tickers and add some lines that look like this
0.vmware.pool.ntp.org
1.vmware.pool.ntp.org
2.vmware.pool.ntp.org
From here, save the file and restart ntp (service ntpd restart).
Questions? Drop a line in the comments.
Sources: Tripwire KB, VMware KB, and some random UseNet/Mailing list post about ntpd.
I'm not sure each line should have 'server' at the beginning.
According to: Installing and Configuring NTP on VMware ESX Server (http://kb.vmware.com/selfservice/microsites/sea…)
Edit /etc/ntp/step-tickers so that the file looks like the following example:
0.vmware.pool.ntp.org
1.vmware.pool.ntp.org
2.vmware.pool.ntp.org
Looks like the tripwirekb article needs to be corrected to conform to the vmware kb.
Good catch. Post has been updated, and I've pinged Tripwire.
Me and my buddy had a discussion about this and its importance the other night, and we even raised a bet over it. He was leaning on its value while I debated him otherwise. However, upon reading this post of yours, I must admit that I stand corrected. Guess I owe my buddy a six pack. 🙁 Nevertheless, I got to know more about it, even though I somewhat got kicked in the balls over it. lol
Thanks for making things clear, I totally appreciate it!
Thanks for making things clear, I totally appreciate it!
> I'm not sure each line should have 'server' at the beginning.
It works with or without. I suspect that the server directive is simply ignored.
CentOS and RHEL have this by default. Any ideas why it's missing from Ubuntu?
Hey Matt,
Looking into this as I'm not quite sure either. What verion of Ubuntu are
you running?
Hey Matt,
Looking into this as I’m not quite sure either. What verion of Ubuntu are
you running?
is this needed in esx 4.1 it seems as though this is no longer needed in the new version of esx
Starting from RHEL 6 step-tickers is no longer checked at ntpd service startup.
You need to do “chkconfig ntpdate on” to have it made at startup.
“service ntpdate start” allows you to do it on demand (warning ntpd has to be stopped).
Hey Bunchc,
I haveCentOS and I have installed ntp, but there is no file named
“step-tickers” in /etc/ntp/ present.
Please help me.
Thanks,
Have been on leave, sorry for the delay. Depends on which version of Cent/RHEL you are using, they may no longer be required.