From owner-freebsd-cloud@freebsd.org  Sat Mar 25 21:28:44 2017
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Subject: Re: Issues with clock skew on GCE
To: Prakhar Goel <newt0311@gmail.com>, freebsd-cloud@freebsd.org
References: <CABa1M210++ioEM5LQ=Lx+rbsn3d4bWLojUc4T3WusOH7t-g4cg@mail.gmail.com>
From: Colin Percival <cperciva@tarsnap.com>
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Date: Sat, 25 Mar 2017 21:28:36 +0000
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On 03/25/17 14:20, Prakhar Goel wrote:
> Has anybody noticed clock skew on g1-small instances? I have two and
> both show substantial clock skew (as much as several days after only a
> few days running). The n1 etc... instances I have seem to be fine so
> perhaps this is limited to the shared cpu instances only?

I'm an EC2 guy rather than a GCE guy, but I'd suggest looking at the
kern.timecounter sysctl.  Clock skew on virtual systems is something
easily seen as a result of TSC fiddling.

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid