Feb 28 ’12

Linux on System z:  What Happens When You Ask Nicely

by David Boyes, Ph.D. in z/Journal

Now that the holidays are over, it’s a good time to think about what happens when we ask for things nicely. From my last column (Winter 2011/2012), I have some really outstanding things to report.

First, the kind folks at IBM Germany reminded me that Layer 2 VLAN support for hipersockets was added awhile back. z10s and higher have this capability, although it’s uncertain to me whether the operating systems other than z/VM and Linux have support for actually using it. There’s no capability to bridge from Layer 2 to Layer 3 guests, so I guess that limits its use to Layer 2-aware operating systems. It also requires specific microcode loads, so check with your IBM representative to determine whether you have the capability to do this. It dramatically simplifies use of hipersockets. Get one to work and use it as the base for a Layer 2 virtual switch, instead of that nightmare of attaching hipersocket connections directly to virtual machines.

Second, the kerfuffle on Oracle Cluster File System (OCFS) I reported earlier seems to have had a happy ending. The major distributions have provided alternative methods to service OCFS, and the confusing language coming from Oracle has been revised to clarify that they were discussing support on other distributions. My mistake on that confusion is noted, and I’ve performed the expected abasement and lustration to the gods of chaos and confusion. We have some research in progress on distributed file system alternatives and performance of same; perhaps I can get some data out that others can use to confirm our conclusions. Look for that in the next few months.

Third, a new release of the z/VM and Linux Cookbook series is available. For those of you who haven’t seen one, this book is a private project of some IBMers led by Mike MacIsaac and distribution vendors to collect a cookbook of best practices for building a z/VM and Linux server farm, system management techniques, and a whole lot more. The announcement and URL can be found at www.vmworkshop.org/node/72.

Literally dozens of people in the IBM and VM/Linux community contributed material, expertise, and reviews—a huge effort for the good of the community. The document and all the sample code and EXECs are available for download. I highly recommend this document; it’s comprehensive, concise, and superbly edited, and at 400 pages, it’s a great companion to the IBM Getting Started With Linux book that came in your box of manuals with your z/VM license.

Last, I recently received a request for a customer recommendation letter to be put in the file of an IBMer at his or her 25th anniversary with IBM. Apparently, it’s also the custom to put those letters in a binder to be presented to the IBMer. I think it’s a nice custom and I’d like to call on the community to recognize the people who work with us. While their time may not always be available to us, they do deserve recognition as the people who make things work. Take the time to send a note to your IBM rep that tells them we need their time, and we value their expertise. If an IBMer helps you out, make sure that gets to their manager. For IBM, that’s the way they rate requests to use their money, and customer support is supposed to tell them what you really want. Speak up, and tell them. It’s good for all of us.