Gentoo Archives: gentoo-dev

From: Bill Kenworthy <billk@×××××××××.au>
To: gentoo-dev@l.g.o
Subject: Re: [gentoo-dev] Signed push & clock drift rejection
Date: Mon, 18 Jul 2016 23:35:03
Message-Id: 578D6792.6080607@iinet.net.au
In Reply to: Re: [gentoo-dev] Signed push & clock drift rejection by Mart Raudsepp
1 On 19/07/16 07:06, Mart Raudsepp wrote:
2 > Ühel kenal päeval, E, 18.07.2016 kell 16:25, kirjutas james:
3 >> On 07/18/2016 03:03 PM, Marc Schiffbauer wrote:
4 >>> * Rafael Goncalves Martins schrieb am 18.07.16 um 03:12 Uhr:
5 >>>> On Sat, Jul 16, 2016 at 11:33 AM, Andrew Savchenko <bircoph@gento
6 >>>> o.org> wrote:
7 >>>>> Set it for a minute or two. This will protect from commits from
8 >>>>> really out-of-sync systems (like 14 days mentioned above) and
9 >>>>> will
10 >>>>> keep usablity hight for others.
11 >>>>
12 >>>> I second this "request" :)
13 >>>>
14 >>>> remote: Your system clock is off by 6 seconds (limit 5)
15 >>>
16 >>> Why not fix your system clock? No ntpd running?
17 >>>
18 >>> Check 'ntpq -pn'
19 >>>
20 >>> -Marc
21 >>>
22 >>
23 >> net-misc/openntpd is simple and might do the job well enough, or is
24 >> net-misc/ntp a hard requirement ?
25 >>
26 >
27 > or just
28 >
29 > systemctl enable systemd-timesyncd.service
30 > systemctl start systemd-timesyncd.service
31 >
32 > if you are fortunate enough to run systemd.
33 > If not, well, some other ntp client indeed, no need to debate fortunes
34 > further :)
35 >
36 > If there's no RTC clock ticking and syncing during/after suspend,
37 > something seems off in my experience. Disabled ACPI? :D
38 >
39 > I didn't find any indications of why this is actually a problem in the
40 > announcement or replies, and I couldn't read the backlog for the
41 > explanation that I saw might have skimmed through. I think if we want
42 > to nitpick what the actual drift allowed is, we need to know the
43 > reasons this restriction is needed and what could be the difference to
44 > that unspecified potential rsync issue between a seconds of drifts and
45 > a couple minutes or an hour or so of drift.
46 > I'm sure infra will adjust if possible and choose what's best :)
47 >
48 >
49 > Mart
50 >
51
52 or configure ntpd appropriately - look into the -g argument to ntpd, or
53 "tinker panic 0", burst and iburst in the config file to quickly step
54 if the error is greater than 1000s. Chrony has worked better than ntp
55 for me in libvirt managed qemu instances but may still not sync for
56 quite awhile.
57
58 If you have a raspberry pi or similar (no hwclock) use swclock instead
59 to prime the system time with a close value - just ran into this on a pi
60 where the default date (1st Jan 1970) was outside a networks certificate
61 range so it couldn't get a network connection to set the time so it
62 could access the network :) Systemd can do this too - but I have read
63 (cant find the reference) that its time mechanism is non-standard (who
64 would have thought!) and is very primitive compared to alternatives -
65 good enough for non-critical applications though.
66
67 BillK