svn commit: r326095 - head/usr.sbin/bsdinstall/scripts

[Rodney W. Grimes]

> On Thu, 23 Nov 2017 06:56:50 -0800 (PST)
> "Rodney W. Grimes" <freebsd at pdx.rh.CN85.dnsmgr.net> wrote:
> 
> > > 
> > >  Hi Devin,
> > > 
> > > On Thu, 23 Nov 2017 01:33:39 -0800
> > > Devin Teske <devin at shxd.cx> wrote:
> > > 
> > > > 
> > > > 
> > > > > On Nov 22, 2017, at 11:15 PM, Emmanuel Vadot <manu at bidouilliste.com> wrote:
> > > > > 
> > > > >> On 2017-11-22 17:38, Ian Lepore wrote:
> > > > >>> On Wed, 2017-11-22 at 15:27 +0000, Emmanuel Vadot wrote:
> > > > >>> Author: manu
> > > > >>> Date: Wed Nov 22 15:27:47 2017
> > > > >>> New Revision: 326095
> > > > >>> URL: https://svnweb.freebsd.org/changeset/base/326095
> > > > >>> Log:
> > > > >>>   bsdinstall: Add ntpdate option
> > > > >>>   
> > > > >>>   When you install a computer for the first time, the date in the CMOS sometimes
> > > > >>>   not accurate and you need to ntpdate as ntpd will fail a the time difference
> > > > >>>   is too big.
> > > > >>>   Add an option in bsdinstall to enable ntpdate that will do that for us.
> > > > >>>   
> > > > >>>   Reviewed by:    allanjude
> > > > >>>   Differential Revision:    https://reviews.freebsd.org/D13149
> > > > >>> Modified:
> > > > >>>   head/usr.sbin/bsdinstall/scripts/services
> > > > >>> Modified: head/usr.sbin/bsdinstall/scripts/services
> > > > >>> ==============================================================================
> > > > >>> --- head/usr.sbin/bsdinstall/scripts/services    Wed Nov 22 15:18:11 2017    (r326094)
> > > > >>> +++ head/usr.sbin/bsdinstall/scripts/services    Wed Nov 22 15:27:47 2017    (r326095)
> > > > >>> @@ -46,6 +46,8 @@ DAEMONS=$( dialog --backtitle "FreeBSD Installer" \
> > > > >>>      local_unbound "Local caching validating resolver" ${local_unbound:-off} \
> > > > >>>      sshd    "Secure shell daemon" ${sshd_enable:-off} \
> > > > >>>      moused    "PS/2 mouse pointer on console" ${moused_enable:-off} \
> > > > >>> +    ntpdate    "Synchronize system and network time at bootime" \
> > > > >>> +        ${ntpdate_enable:-off} \
> > > > >>>      ntpd    "Synchronize system and network time" ${ntpd_enable:-off} \
> > > > >>>      powerd    "Adjust CPU frequency dynamically if supported" \
> > > > >>>          ${powerd_enable:-off} \
> > > > >> The right way to enable a time-step at boot is to set the rc conf
> > > > >> variable ntpd_sync_on_start to YES.  ntpdate has been deprecated for
> > > > >> *years*.
> > > > >> -- Ian
> > > > > 
> > > > > Hi Ian,
> > > > > 
> > > > > Thanks I didn't know about option -g (nor ntpd_sync_on_start), this bring a few questions :
> > > > > 
> > > > > - Is there any reason to not always use -g for ntpd ? As a lambda user I just want my time to be set, no matter what.
> > > > > - Should we remove ntpdate in -current before 12 if it's deprecated ?
> > > > > 
> > > > > I'll make the necessary changes according to your (or others) answers.
> > > > > 
> > > > 
> > > > I would not remove ntpdate.
> > 
> > I concur, as ntpdate is trivial to use, ntpd -pg requires a proper /etc/ntp.conf,
> > though that is trival too you well not get what you want if you do not have
> > that.
> 
>  From the website you linked after they say to use :
>  ntpd -gqc /dev/null server1.name.net server2.name.org server3.name.com
>  for use without ntp.conf.

I do not think you want to do that, as if you read just a bit further you see:

	Possible hitch: ntpd will step the time adjustment if it is more
	than 128ms (default). This means that a 128ms adjustment will take
	256 seconds to apply. We want an option to step any initial offset,
	I suspect.

So even the ntp folks seem to have issues with replacing ntpdate....

>  Also we do provide an ntp.conf so ...

We do, a template, all commented out, and does not work for
machines behind strong firewalls that wont allow ntp out
to the net but have internal ntp servers that are used for
such things.

Well maybe not all commented out, I think it defaults to
some public pools.  I believe it would be missing iburst
for use with ntp -pg

> 
> > > > Is there a way to make ntpd sync and then quit immediately?
> > > 
> > >  Just by reading the man I see the -q option which does exactly that.
> > >  Setting both -q and -g should have the same behavior than ntpdate (not
> > > tested).
> > 
> > ntpd -pg is the preferred method per the ntp.org documentation:
> > https://support.ntp.org/bin/view/Dev/DeprecatingNtpdate
> 
>  -gq like I said but it's good to have an official reference.
> 
> > > 
> > > > If not, sounds like ntpdate serves a purpose not filled by ntpd.
> > > > 
> > > > Valid case is someone running a VM that gets paused for days, weeks, or even months at a time. On such a VM it may make more sense to let the clock be only sporadically managed in an adhoc manner.
> > > > 
> > > > I personally like to use ntpdate on said VMs because I generally set a timeout on my ssh-agent in said VMs and by managing the clock manually allows me to better control keys loaded.
> > > > 
> > > > Pretty sure other people may have other reasons for non-daemonized clock management.
> > > 
> > >  That's why I asked :)
> > 
> > I think that the ntp distribution still contains ntpdate, so long as that is true
> > we should continue to include it in FreeBSD.  When/if they remove it from the
> > official ntp distribution then this issue shall need a revist.
> 
>  I haven't checked.
>  We can also add a shell script that does what I quoted above.

We could, but that gets us the bug of time wont be stepped if
correct within 128mS and causing a long slow 4 minute slew event.

> > > > Devin
> > > Emmanuel Vadot <manu at bidouilliste.com> <manu at freebsd.org>
> > Rod Grimes                                                 rgrimes at freebsd.org
> Emmanuel Vadot <manu at bidouilliste.com> <manu at freebsd.org>
-- 
Rod Grimes                                                 rgrimes at freebsd.org