I have an SNTP server running on OS/390, which is getting it's time from
the local OS, which is kept in synch by our sysplex timers. Linux then
uses ntpdate against this os/390 time source I think I have it going every
30 minutes. Probably overkill.
|---------+---------------------------->
| | James Tison |
| | <[EMAIL PROTECTED]|
| | m> |
| | Sent by: Linux on|
| | 390 Port |
| | <[EMAIL PROTECTED]|
| | IST.EDU> |
| | |
| | |
| | 11/04/2003 09:25 |
| | AM |
| | Please respond to|
| | Linux on 390 Port|
| | |
|---------+---------------------------->
>------------------------------------------------------------------------------------------------------------------------------|
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| To: [EMAIL PROTECTED]
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| cc:
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| Subject: Re: NTP (Time Synchronization) in the Z environment
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>------------------------------------------------------------------------------------------------------------------------------|
I ntp sync my z/VM Linux guests from an external source. I have no idea
what hardware the ntpd server is running, but I assume it's native,
dedicated hardware. I run 'ntpdate' via cron every 30 minutes on my z/VM
guests, and am only seeing between 1 and 4 ms corrections (randomly) at
every interval. For those reasons, I wouldn't run my ntpd on a z/VM guest.
Some of the lower quality Chinese mobos I've seen on peecees don't make for
good ntpd servers, either. You need a very stable internal clock with very
little drift. Ultimately, you want to ntp sync with a server that gets its
value either directly or indirectly from tick or tock (.usno.navy.mil) --
that's fed off of the US Naval Observatory's atomic clock.
--Jim--
James S. Tison
Senior Software Engineer
TPF Laboratory / Architecture
IBM Corporation
"A bird in hand is safer than one overhead."
