>>> On 2/9/2009 at 7:04 AM, Erling Ringen Elvsrud <[email protected]> wrote: > Hello list, > > I work as a Linux systems administrator. Currently we have about > 200 virtual (vmWare) and 40 physical linux servers. Most of these > servers are used > for WAS (Websphere appserver), a few for WPS (Websphere process server), > and a few for other uses. > My employer is condidering zLinux (on a z10 BC mainframe). I have no > experience with mainframe, z/VM or zLinux. > > Can you describe how you use zLinux? What kind of software do you run > on zLinux? how many zLinux instances per IFL, how much memory? > What kind of workloads do you think realizes most economic benefits on > zLinux?
Looking at our customer base, I see a _lot_ of WebSphere (of various flavors), Oracle, and SAP. There are some people running things like file servers, simple web servers, etc., but in the majority of cases, management has gone for the big return on investment by putting up big applications. No surprise, but these are the workloads that save the most money, even when compared to virtualization on midrange hardware. With license charges for Oracle, SAP, DB2, WebSphere, etc. being based on the number of processors, and each license being so hideously expensive, it doesn't take much to generate some real savings, particularly when talking about how many dev/test/QA/DRA systems you might have. Consolidating those low-use systems onto a mainframe can be very significant money savers. > If you are familiar with other virtualization alternatives, can you > compare zLinux on zVM with them? (for instance cost, performance, > simplicity of administration, etc). There's really no comparison. A single instance on z/VM can handle literally hundreds of Linux guests, providing enough hardware resources are available (CPU, memory, etc). There's no built-in GUI to z/VM (but you can spend an awful lot of money to get one that probably still won't do everything you need. There is a no-cost one, but it only does some very basic things.) You'll need to get used to a different text editor than anything you've seen before (Xedit). In other words, a fair number of adjustments, but nothing other people haven't dealt with. I would say that with a minimum of add-on tools (A security system, a directory manager, performance monitoring and management tool), the amount of effort to manage z/VM will be considerably less than managing VMware, for example. If for no other reason than you'll only be managing one or two z/VM systems, not dozens of them. I'm not sure how cost compares. My understanding is that the higher-end versions of VMware can get quite pricey. The price for z/VM depends on the machine type you're using. If it's a z9, the list price is $22.5K per processor, plus annual support and maintenance charges. (Very few people pay list price.) The list price for a z10 is (I believe) $27K per processor, plus annual support and maintenance charges. (On the other hand, the processors on a z10 are far more than 20% faster than on a z9.) The price per processor goes down with processor #4, down again with #7, etc. You can get some more information from Reed Mullen's presentation on z/VM from SHARE111 at http://www.vm.ibm.com/devpages/MULLENRA/SHARE111.pdf The amount of power, floor space, cooling, network gear, and so on needed for Linux running on z/VM is considerably less than with virtualization on midrange hardware. Not as big of a difference as with all discrete midrange systems, but still significant. Mark Post ---------------------------------------------------------------------- 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
