Well, yes and no and yes and no and it depends. For a long time, one of the benefits of Linux/390 on the mainframe was the consolidation of many small servers onto fewer engines. This is a cost thing. A license for a server is the same for Intel as the manframe. And with VM (ok I will even include LPARS), you can have multiple "servers" with much lessor license cost.
For the first few years, we were warned about putting large workloads (read CPU intensive) on the mainframe. The MIPS are still cheaper on Intel. However, over the last 9 months, there have been, at least, two discussions of shops putting very large Linux workloads on the mainframe. One shop had 9 IFL engines running 7 Linux images. To me, that sounds like a large work load, not server consolidation. Another shop, about 6 weeks ago, talked about a large Linux/390 application, without VM taking a large number of IFL engines. By the tone of the discussion, it was the best I/O delievery platform available for their application. So, based on the above two cases, I nolonger reject the notion of large workloads under Linux/390. I now believe that, when it comes up, it is a subject to look at. Perhaps, in certain cases, it is cost justifiable. Perhaps it is a more expensive solution, but the best solution. Being a VM bigot, both these cases left VM out in the cold. I understand why. $45K per engine plus $11K/engine/year which is good for many "little" workloads, but with only a few engines, LPAR seems to be worth it. (Ok it's basically free) And with IBM's "capacity on demand", that adds a lot of cost savings if you have a highly variable workload. Tom Duerbusch THD Consulting >>> [EMAIL PROTECTED] 09/15/03 07:19AM >>> I have been under the impression for some time that zLinux, while a terrific solution for some applications, may not be the best solution or fit for "large workloads". Certain colleagues of mine have begun evaluating where zLinux might fit in our organization should we choose to go in that direction. They have listed Linux on Intel as suitable for small workloads and zLinux as suitable for large workloads. In fact I have been of the understanding that zLinux would be a solution for many guests installed under z/VM running small to medium workloads, i.e web server farm. I keep thinking back to the Linux 2.6 kernel which allows for a larger number of CPUs, more memory and more disk to be addressed. In addition I see Los Alamos implementing 2000+ AMD CPUs for almost 12 trillion operations per second of processing power (This information from ZDNet regarding Lightning, August 14, 2003). To me that sounds like a large work load on an Intel type platform. So my question is, to those of us using zLinux, what are we seeing it implemented for and where is working best? Thank you, This information will prove very helpful. Eric Sammons (804)697-3925 FRIT - Infrastructure Engineering
