ntpd initial time set failure...any way to prevent this?

[tld]

On my mythtv backend system, I'd running net-misc/openntpd-6.0_p1 and I'm using the default NTP servers:

[Ionen]

I don't really know much about opentpd since I use ntp.org's ntpd (with -g option to allow large time changes), maybe it would work better for you. Also if you have a reliable LAN machine that's always up you could have it run a ntpd server to sync with (that's what I do, and it's the only one that will pool remote ntp servers if it's up rather than every machines on the network doing it, will provide a baseline should internet or other ntp servers be down if a machine is booted way off).

[freke]

ntpd comes with ntp-client (ntpdate) which is cabable of making big adjustments to the clock.

https://wiki.gentoo.org/wiki/Ntp

and ntpdate has a timeout option - https://linux.die.net/man/8/ntpdate

I've always had ntp-client start before ntpd on my computers to make the big adjustment if needed before starting ntpd (ntp-client is a onetime adjustment).

EDIT:
oops - didn't notice - openntpd, don't know about that :/

Is dns available when ntpd tries to start - i've had that problem?

[tld]

Thanks for the replies!...yea, DNS certainly should be available at that time. Also note that this usually doesn't happen but it did in this case, and I'm pretty sure it happened to me another time way back.

I actually used to use net-misc/ntp way back and for the life of me I have no idea why I switched. I though I recall that having to do with recommendations because of security concerns, but I can't find anything to that affect. Frankly there are a LOT of things I don't like about opennptd. For example:

The only means of manually setting the date even if dramatic changes are needed is to do what I have here. That is to start the service with -s. However that means that you CANNOT specify a different server for this purpose as compared to what you have in your config. For that reason I had to abandon using my mythtv backend as an NTP server for the frontend, because any time I needed to reboot both, openntp would consider the backend NTP server as not synced and the frontend wouldn't adjust. With net-misc/ntp I could configure ntpclient to use an internet ntp server for that purpose.

Maybe I'll switch back. I've always been bit annoyed with many aspects of openntpd frankly.

Tom

[Ionen]

net-misc/ntp is still getting updates which I'd assume is taking care of security issues if any (last stable release in March 2019). openntpd is still getting active development, but the last actual release was in October 2017 (the gentoo stable release is from 2016), not sure what's the status of this.

1-time boot-time checks is just not something that can be fully relied on either way, something may always be unavailable for one reason or another (being over LAN rather than remote at least helps but even then).

[tld]

I found some notes I had from back when I switched, and now I'm recalling more about this, but I'm a bit confused. Didn't the ntp project switch from the ntpdate program to sntp? I'm sure that was the case. Did ntpdate come back or something. I recall that sntp program was really confusing.

EDIT: Found this: https://support.ntp.org/bin/view/Dev/DeprecatingNtpdate

It sounds like ntpdate is still in use after all this time though(?). Confusing.

Tom

[tld]

I've found some old posts and now I recall why I switched from ntp to openntpd. When I used net-misc/ntp I was using the sntp program for ntp-client, and was having occasional failures:

https://forums.gentoo.org/viewtopic-t-987724.html

However later I discovered that this was simply because I was attempting to sync my MythTV frontend to the backend computer, which would always fail if I'd recently rebooted the backend. This is because the backend was considered to be not synced, but the sntp program wasn't giving be any meaningful errors to indicate as much. See the last post here:

https://forums.gentoo.org/viewtopic-t-1008332-start-0.html

So arguably my reasons for switching really don't apply. That brings me back to my question about the sntp program vs ntpdate:

[tld]

Ultimately I've pretty much decided to stick with openntpd, especially after re-reading the things I ran into with sntp. As noted by Ionen, those boot time checks really can't be fully relied on regardless. It would be nice if the openntpd ntpd offered some timeout option for it's -s option. What is nice however is that, in the rare case where the time set fails, given that openntpd handles this in the daemon executable itself, fixing it is just a matter of restarting the service.

In the process of looking into this I found a nice bash command to check the current UTC from nist.gov that can be compared to "date -u":

[Ant P.]

If you want an ntpd that just works, use chrony.

[tld]