McKown, John wrote: >>-----Original Message----- >>From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On >>Behalf Of Jon Brock >>Sent: Wednesday, July 13, 2005 8:29 AM >>To: [email protected] >>Subject: Re: SLES Service Pack Released >> >> >>Perhaps it is just the geek in me, but I think this is cool: >> "SP1 adds mainframe capitalization with CPU hotplug >>support for IBM S/390 >> and zSeries machines, enabling a physical CPU to be >>exchanged during >> runtime and keeping the system up and running even >>through server repairs." >> >> >>Jon (Either the webserver is seriously out-of-date or someone did not read it properly, but this really should read 'SP2 released'. Anyhow.)
> > Hum, > > Under LPAR or z/VM, I would have thought that would be "transparent" due > to the "Physical CP" to "Logical CP" mapping done by them. Also, 99% of > the time, when a CP fails, the hardware automatically switches to a > spare CP (if there is one) with no OS intervention at all. I think that > the OS gets some sort of interrupt so that it can record the error, but > no error recovery is required by the OS in this case. Sort of. The linux kernel does get notified whenever a CPU goes offline; but the main trick here is that you can add and remove CPUs to a running image. Without having to reboot. Thus you can really have computing power on demand. Or implement load-balancing across several guests. Well, the z/VM has to support that feature, of course. IIRC z/VM 5.1 does. Unfortunately hotplugging memory doesn't work as well; z/VM still wants to reset the system after a 'def store'. Cheers, Hannes -- Dr. Hannes Reinecke [EMAIL PROTECTED] SuSE Linux Products GmbH S390 & zSeries Maxfeldstraße 5 +49 911 74053 688 90409 Nürnberg http://www.suse.de ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
