What's with our current confusion between adjectives and adverbs? It seems to be getting more prominent everywhere. I don't think it's an influence from EFL like "learnings".
First link in the article:
The school for sysadmins who can’t timesync good
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Re: The school for sysadmins who can’t timesync good
#22Earlier quoted context omitted.
I cheat and have an authoritative NTP server locally and then override dns for pool.ntp.org and friends. Then at least if I’m off we’re all off together.
For bonus points, hook up a GPS with a PPS output to the local one so it's stratum 1.
I do this at home with a Pi, it was a fun project.
Re: The school for sysadmins who can’t timesync good
#23What's with our current confusion between adjectives and adverbs? It seems to be getting more prominent everywhere. I don't think it's an influence from EFL like "learnings".
First link in the article: http://www.imdb.com/title/tt0196229/quotes?item=qt0375868
Hah, that'll teach me! But people are using this phrasing more commonly, thinking different and so on..
Re: The school for sysadmins who can’t timesync good
#24It’s a good read, and I really wish time was always that simple. Sometimes you have multiple platforms on different clock systems and distributed systems running across them. Did you know google and amazon smear leap seconds? GPS/Galileo/that-China-one don’t have leap seconds (but all are different TAI offsets) but that Russian GPS one does have leaps. They all have slightly different versions of utc. Most of the tim…
You can nowadays buy a chip-scale atomic clock for $2000, which is a modest fraction of the price of an entire server. Every datacenter should have one.
Re: The school for sysadmins who can’t timesync good
#25The title makes it seem as if there's some architectural thing people don't understand. It's a good extensive article, but it's too much information for most sysadmins.
If you really need high precision time synchronization, for example when triangulating signals on different machines, you should look at ptpd (https://github.com/ptpd/ptpd).
Re: The school for sysadmins who can’t timesync good
#26Earlier quoted context omitted.
The Win32 daemon only provides coarse time adjustment. Basically doing an ntpdate to adjust the clocks once per day or so. Good enough for domain logins, but a couple orders of magnitude worse than the regular NTP protocol. Of course on Linux most of the arcane details of the ntp daemon aren't relevant because most distros end up running SystemD with timesyncd instead. I discovered this when all of my T1 time sources…
> The Win32 daemon only provides coarse time adjustment. True in XP (it was a crappy SNTP implementation), but it was rehauled significantly in Windows 10/Server 2016 and above because of Azure requirements. It can now guarantee accuracy within 1 second at all times and even higher when the NTP server is local ( https://docs.microsoft.com/en-us/windows-server/networking/w... )
That’s still absolutely rubbish.
Re: The school for sysadmins who can’t timesync good
#27What's with our current confusion between adjectives and adverbs? It seems to be getting more prominent everywhere. I don't think it's an influence from EFL like "learnings".
"who can’t timesync good"? It's really poor writing.
Re: The school for sysadmins who can’t timesync good
#28Earlier quoted context omitted.
> most distros end up running SystemD with timesyncd instead which tends to be "good enough" for the average desktop user, but anything even vaguely server-ish should run a full NTP implementation such as chrony and not an SNTP one such as systemd-timesyncd. a few years ago at $dayjob we had a fleet of CoreOS hosts. CoreOS, at the time, defaulted to systemd-timesyncd using pool.ntp.org addresses. our CoreOS hosts, ob…
I cheat and have an authoritative NTP server locally and then override dns for pool.ntp.org and friends. Then at least if I’m off we’re all off together.
> I cheat and have an authoritative NTP server locally and then override dns for pool.ntp.org and friends.
Generally if you've made the effort to have internal recursive DNS server(s) for your network, then just enable NTPd or chrony as well and have a single source of Time Truth for your network.
Point to ≥4 NTP servers, even using pool.ntp.org, and you probably don't have to worry about false ticker(s) either.
Re: The school for sysadmins who can’t timesync good
#29At least its not time syncing for ants
Re: The school for sysadmins who can’t timesync good
#30It’s a good read, and I really wish time was always that simple. Sometimes you have multiple platforms on different clock systems and distributed systems running across them. Did you know google and amazon smear leap seconds? GPS/Galileo/that-China-one don’t have leap seconds (but all are different TAI offsets) but that Russian GPS one does have leaps. They all have slightly different versions of utc. Most of the tim…
> GPS/Galileo/that-China-one don’t have leap seconds (but all are different TAI offsets) but that Russian GPS one does have leaps. They all have slightly different versions of utc.
This is not wrong, but it's missing a large chunk of information. All non-UTC-based geonavigation satellites also broadcasts both the offset between internal and UTC and if there's an impeding leap second.