[OT] NTP servers - was Re: Kernel clock issue "Clocksource tsc unstable"

[Derek Broughton]

Rashkae wrote:

> NoOp wrote:
> 
>> 
>> I also purposely remove the ntp.ubuntu.com/canonical servers; I' don't
>> mind providing some data, but sync'ing to them just seems a little big
>> brother/Microsoft'ish to me.
> 
> Unless you're doing something that's extremely time sensitive (such as
> synchronizing to those time based RSA security tokens) I don't really
> see the point to synchronizing with ntp at all.   Any functioning clock
> should be able to keep track of wall time within a few seconds accuracy
> per month.

And on that note, I'll mention my most recent clock issues.  After replacing
my laptop a couple of weeks ago, I was unable to immediately install Ubuntu
(only had hardy install disc, which didn't have kernel support for AHCI
disks - turned out all I really needed to do was change the BIOS setting
from AHCI to IDE, but I digress).  So I installed Kubuntu 8.04 in a
VirtualBox, which automatically synchronizes the VM clock to the host.  The
Windows host gets synchronized when I'm at a client's to their often-wrong
internal time server.  Now, the VM runs all the things I always ran
natively, including an IMAP server (dovecot) which aborts about once a day
because Dovecot is paranoid about backward time changes, and shuts itself
down whenever that happens - and the default ntpdate setup on Ubuntu
resyncs every time a network device is upped.

So, I'd agree that ntp is serious overkill for most personal-use computers 
and even ntpdate only needs to be run at boot (or resume-from-hibernate)
time.  I would _always_ recommend syncing times at start-up, because some
hardware clocks are notoriously unreliable when the machine is powered
down.
-- 
derek