The level of redundancy is not the same in the Intel/AMD world as it is in the mainframe. In many cases this does not matter. You only need the redundancy if something goes wrong. In many cases an Intel based server is very reliable. It is hard to compare CPU power, but it seems to me that Intel has a big advantage in CPU speed right now.
Software is another matter. I am not a fan of Windows, and I find the number of hangs to be annoying. It does work well enough for most web applications though. Linux seems to be very reliable, although I don't have much direct experience with it. z/OS has its problems. When we went from a weekly IPL to a bi-weekly IPL our system crashed after about a week and a half because CSA was exhausted. If I may ramble on a bit: one thing I have noticed is that all systems I have worked with have one common problem, which is programs that try to access memory regions outside of the allocated virtual memory for the process. On Windows this results in the famous general protection fault, on Unix it results in the famous segmentation fault, and on z/OS it is the famous SOC4. I wonder if there isn't a better way to deal with this problem then just aborting the program. Users find this problem really annoying. -----Original Message----- From: Eric Sammons [mailto:[EMAIL PROTECTED] Sent: Tuesday, October 28, 2003 10:27 AM To: [EMAIL PROTECTED] Subject: Re: Perpetuating Myths about the zSeries I have heard the story line, "If you have high transaction volume, then you don't want Big Blue IRON." Well my question then is, what is a transaction? Is this a computation, is this prime number generation, is this high volume websites, or is this is a large database with a Tbyte of data running 1000s of SQL statements in a brief moment of time, for example a web application adding users to a secure way ldap (back-end is db2)? So what is a transaction? When is a instruction not a transaction and if everything is in some way a transaction what exactly is Linux on the MF good for, other than supporting a virtual environment of previously installed and largely under utilized distributed systems? Would I want to run 100 systems in a given z/VM each with some number of JVMs, yes WebSphere? We are talking about putting 6 JVMs onto a single Linux guest. I am looking forward to this as during our POC (proof of Concept) we never tested with more than 1 may be 2. On the topic of availability I am not sure I buy the whole MF is better than 80x86 or Intel / AMD 64 server hardware. Today, everything is redundant and everything is hot swapable. What is different is to get a new stick or replacement stick of memory for the MF could cost you and automobile and you won't find that stick of memory at the local computer store. Thoughts??? Eric Sammons (804)697-3925 FRIT - Infrastructure Engineering Phil Howard <[EMAIL PROTECTED]> Sent by: Linux on 390 Port <[EMAIL PROTECTED]> 10/28/2003 01:14 PM Please respond to Linux on 390 Port To: [EMAIL PROTECTED] cc: Subject: Re: Perpetuating Myths about the zSeries On Tue, Oct 28, 2003 at 11:21:23AM -0600, Adam Thornton wrote: | On Tue, 2003-10-28 at 10:57, Jim Sibley wrote: | > The speed of the top of the line zSeries has increased | > at four fold in the last 3-4 years. | | I'd be amazed if Intel hasn't done at least this well too. It probably has. But CPU power isn't the whole story, either. I'd ask about how fast a machine built around an Intel/AMD CPU can deal with multiple devices concurrently transferring data for read or write I/O operations. If you need sheer computation power, zSeries is probably not right for you (how about PPC?). But if you need a large, high traffic, high uptime, database, you don't really want the kinds of machines typically built around Intel CPUs. -- ----------------------------------------------------------------------------- | Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ | | (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ | -----------------------------------------------------------------------------
