I don't think I'd want to depend on a zLinux system under VM as a stable time source. I seem to recall that Linux only sets the software clock to match VM at boot time, and occasionally misses clock interrupts (especially at high load), causing the software clock to drift over time.
I know I've seen significant drift on my SuSE SLES7 systems (which is the reason I set up NTP in the first place), but I haven't checked the SLES8 ones. We run NTP on the zLinux systems, but sync to an external time source. You could do that, and have your other zLinux systems sync to it. On x86 boxes there's a utility called "hwclock" that can read and update the PC hardware clock, but I don't know if there's an equivalent to sync zLinux against VM time without a reboot. > -----Original Message----- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] Behalf Of > David Boyes > Sent: Tuesday, November 25, 2003 10:31 AM > To: [EMAIL PROTECTED] > Subject: Re: [LINUX-390] (S)NTP Server Under Linux for Z > > > > Is there a method to use Linux on 'Z' as an NTP Server so > > that We can synchronize our w2k and unix servers to the 9037 > > sysplex timers. For this purpose would there be a difference > > between running in LPAR versus under VM due to differences in > > time offsets etc. > > Sure. Install the xntp server from your Linux distrubution > and point your > clients at it. That's all there is to it. > > You can't set the 390 clock this way (too bad -- that'd be a > nice hack), but > the 390 clock is pretty stable >
