Re: [opensuse] Re: chrony and hwclock
Roger Oberholtzer wrote:
On Tue, 2011-07-19 at 10:44 +0200, Per Jessen wrote:
Hmm, I think it's a system thing too - see /etc/localtime
There are two possible usage scenarios:
1. The hardware is in UTC time, and there is a timezone specified that specifies how to report the local time from the UTC time.
Right.
2. The hardware is in localtime, and there is a timezone specified that specifies how this differs from UTC time.
No, I don't that is an option. It doesn't matter what UTC time when everything is in local time. -- Per Jessen, Zürich (18.4°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Per Jessen wrote:
Roger Oberholtzer wrote:
On Tue, 2011-07-19 at 10:44 +0200, Per Jessen wrote:
Hmm, I think it's a system thing too - see /etc/localtime There are two possible usage scenarios:
1. The hardware is in UTC time, and there is a timezone specified that specifies how to report the local time from the UTC time.
Right.
2. The hardware is in localtime, and there is a timezone specified that specifies how this differs from UTC time.
No, I don't that is an option. It doesn't matter what UTC time when everything is in local time.
No! The kernel always runs in UTC. Or at least it thinks it does and all applications are designed assuming that it does. The hardware clock should preferably be in UTC but may need to be in localtime if the machine dual boots windows. If the hwclock is in localtime, then configuration needs to say what the hwclock offset is. http://linux.die.net/man/8/hwclock The hardware of the machine exists in some time zone and /etc/localtime records the timezone of the physical machine. Each user can then set their own timezone offset from UTC, if it differs from the machine's. A common newbie error is to have the hwclock in localtime, fail to configure the offset (thus defaulting to zero) and everything appears to work. Then a user explicitly sets their timezone and everything goes crazy. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Tue, 2011-07-19 at 10:53 +0100, Dave Howorth wrote:
Per Jessen wrote:
Roger Oberholtzer wrote:
On Tue, 2011-07-19 at 10:44 +0200, Per Jessen wrote:
Hmm, I think it's a system thing too - see /etc/localtime There are two possible usage scenarios:
1. The hardware is in UTC time, and there is a timezone specified that specifies how to report the local time from the UTC time.
Right.
2. The hardware is in localtime, and there is a timezone specified that specifies how this differs from UTC time.
No, I don't that is an option. It doesn't matter what UTC time when everything is in local time.
No! The kernel always runs in UTC. Or at least it thinks it does and all applications are designed assuming that it does. The hardware clock should preferably be in UTC but may need to be in localtime if the machine dual boots windows.
'preferably' yes (and in my case it is). But it is not a requirement. So it must be dealt with.
If the hwclock is in localtime, then configuration needs to say what the hwclock offset is. http://linux.die.net/man/8/hwclock
On openSUSE, it is determined by HWCLOCK, which is in /etc/sysconfig/clock.
The hardware of the machine exists in some time zone and /etc/localtime records the timezone of the physical machine.
Each user can then set their own timezone offset from UTC, if it differs from the machine's.
A common newbie error is to have the hwclock in localtime, fail to configure the offset (thus defaulting to zero) and everything appears to work. Then a user explicitly sets their timezone and everything goes crazy.
Not the case here. Although the case is still undecided... Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Tue, 2011-07-19 at 11:35 +0200, Per Jessen wrote:
Roger Oberholtzer wrote:
On Tue, 2011-07-19 at 10:44 +0200, Per Jessen wrote:
Hmm, I think it's a system thing too - see /etc/localtime
There are two possible usage scenarios:
1. The hardware is in UTC time, and there is a timezone specified that specifies how to report the local time from the UTC time.
Right.
2. The hardware is in localtime, and there is a timezone specified that specifies how this differs from UTC time.
Maybe I should have written that like this (which is what I meant): 2. The hardware is in localtime when the system is booted, and there is a timezone specified that specifies how this differs from UTC time. Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer said the following on 07/19/2011 06:45 AM:
Maybe I should have written that like this (which is what I meant):
2. The hardware is in localtime when the system is booted, and there is a timezone specified that specifies how this differs from UTC time.
That might be your problem. If the setup assumes you scenario #1 but the hardware is actually in #2 that could account for the offset you see. -- "You may delegate authority, but not responsibility." Frank's Management Rule #1. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Tue, 2011-07-19 at 07:40 -0400, Anton Aylward wrote:
Roger Oberholtzer said the following on 07/19/2011 06:45 AM:
Maybe I should have written that like this (which is what I meant):
2. The hardware is in localtime when the system is booted, and there is a timezone specified that specifies how this differs from UTC time.
That might be your problem. If the setup assumes you scenario #1 but the hardware is actually in #2 that could account for the offset you see.
It would. But I have scenario 1 through and through. And I think the system is set up that way in that in /etc/sysconfig/clock I have: HWCLOCK="-u" TIMEZONE="Europe/Stockholm" Which I think it the only place this is set. All else derives from this.
-- "You may delegate authority, but not responsibility." Frank's Management Rule #1.
Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (4)
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Anton Aylward -
Dave Howorth -
Per Jessen -
Roger Oberholtzer