> -----Original Message----- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On > Behalf Of Rich Smrcina > Sent: Monday, February 19, 2007 12:11 PM > To: [email protected] > Subject: Re: zLinux : pro's & con's for running zLinux > natively in a LPAR or under VM > > > For what it's worth the vast majority of Linux environments are using > z/VM. I'm curious about what you don't agree with. > > Running Linux in an LPAR is certainly an option for you and > one that you > are free to use. It certainly will let you run Linux on > the mainframe > for a POC without any additional cost. But the flexibility > of running > Linux with z/VM is very attractive (and useful!) >
The main (only?) negative for z/VM, or perhaps it is a positive for LPAR mode, is that z/VM does not support the VT100 emulator on the HMC that LPAR mode does. This mode is far more useful than the "vm console" which is a 3270 emulating a 3215 AKA a "dumb terminal". The pluses are many: Better use of CSTORAGE. That is, assign it to one z/VM LPAR and let z/VM dole it out. Otherwise, you must specify CSTOR for each LPAR separately and manage it yourself. Much more difficult. Control of devices. Each LPAR running native Linux, in my opinion, should only have the devices connected to it that it specifically needs. This means that when you need to add a new DASD device, you must redo your IOCDS/IODF and do a dynamic activate. Since Linux does not support this, you must do it on z/OS (assuming you don't have z/VM). If you only have Linux, then you're toast and cannot do dynamic I/O activations (or can you do this at the HMC now?). To avoid this, you'd need to "reserve" some DASD to each LPAR for expansion. Personally, I'm way too paranoid to allow "sharing" of DASD between Linux instances. Easy to add a new Linux instance. Fairly low upper limit on the number of LPARs per CEC. IIRC, the z9 systems now allow up to 32 LPARs (but I could be too low on this number). z/VM can have hundreds, if not thousands. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it. ---------------------------------------------------------------------- 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
