On Wed, Jul 29, 2009 at 4:30 PM, Jim Elliott, IBM<[email protected]> wrote:
> As your IBM System z rep, we need to have a discussion on this before you > proceed to look into using CSE. Send me a note (off-list) with some times > you are available (say on Friday this week?) and we can talk. Like you probably meant this off-list as well ;-) But to Sunny and all others considering to take the plunge... Even just implementing XLINK (the part of CSE that you need for this) is not something you do over lunch. It will take time to acquire the skills and set up the procedures, etc. Several IPLs and configuration changes in the right order. Looking at the part of future that IBM already shared with us about z/VM 6.1, it is not unlikely that your investments on implementing CSE today will be wasted once the goodies in z/VM 6.1 become available to you. You may find yourself in the middle of your project with no further supply of the parts you need. If you're not doing CSE today, I would suggest to see whether you can postpone that project (even when you can't go to z/VM 6.1 you might still want something that fits the model that IBM will ship). If you are just looking for ways to avoid accidental starting of Linux on the wrong z/VM system, there are several alternatives. All far easier to implement than CSE (or even just XLINK). Most alternatives are "advisory" in that they give you the right tools to put checks and red tape in the PROFILE EXEC. However, unless your procedures are very robust, even the protection from XLINK is not fool proof either. Only knowing yourself and your co-workers you can tell whether that is enough ;-) #1 define CTCs, implement ISFC and use files in SFS to tell each server whether it should run there #2 use VMNFS to get remote access to a mini disk with the relevant files (may be charged product, dunno) #3 put a PING to itself in the PROFILE EXEC of the guest. When that works you don't want to start Linux #4 keep a list of (guest, system) in a central place and get a fresh copy in the PROFILE EXEC to see if you should run there #5 in the PROFILE EXEC, try to FTP to the other system and see whether you get your 191 R/W - if not, you run elsewhere For each of these, you need to make sure a central table is on both systems (in case one system goes AWOL) but you should not jump to conclusions when there is no affirmative response (eg the VM TCP/IP connection may be gone, but Linux could still be running - the Linux folks talk about STONITH in this context) Rob
