John, On the Intel architecture, the system only references the "hardware" clock at boot time. From there on out, it only uses a "system clock." There are commands to set the hardware clock from the system clock, and vice versa, but they must be issued by you (or one of the system startup/shutdown scripts) for anything to happen otherwise. I am pretty sure the Linux/390 architecture does the same thing. Given that this mirrors the Intel world, I would be a little surprised if anything would be done to mess things up in the future.
Mark Post -----Original Message----- From: McKown, John [mailto:[EMAIL PROTECTED] Sent: Monday, June 02, 2003 4:44 PM To: [EMAIL PROTECTED] Subject: Re: Time Sync Just an observation that may well be very stupid. Since Linux/390 can use NTP to sync time, then it must be that Linux/390 uses a "software" clock instead of the hardware clock (TOD clock). Is this true? If so, what happens if somebody down the line in the kernel maintainers decide that Linux should use the TOD clock instead of a "software" clock? Wouldn't that cause a problem? Or am I worrying about nothing. Unfortunately, I don't have the Linux/390 kernel source around, or I would look myself. I do know where to browse it on the Web, but only if I know the module that I want to view. I can't use grep to find where the clock lives. -- John McKown Senior Systems Programmer UICI Insurance Center Applications & Solutions Team +1.817.255.3225 This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its' content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited. > -----Original Message----- > From: Richard Troth [mailto:[EMAIL PROTECTED] > Sent: Friday, May 30, 2003 4:48 PM > To: [EMAIL PROTECTED] > Subject: Re: Time Sync > > > Steve ... > > Linux/390 will synch time with NTP > just as effectively as Linux on a PC will. > VM does not benefit from this (but is not harmed by it). > I have *not* found NTP to be a resource hog; in fact, it is > designed to be kind of low impact. (Seems to sleep a lot > waiting for time to pass and then check again what time it is.) > > Hopefully you have an internal time reference. > If not, you'll have to find one outside of your network. > (Probably okay, but there's no telling how responsive they > will be since it is a courtesy of sorts.) You're welcome to hit > my personal network (at home). Contact me off list for that addr. > (I'm not in the NTP biz.) > > -- R; >
