SysAdmins Log

So some of you might be thinking… mainframes? Really?

Well I am currently taking a course on mainframes. I must say, they are fascinating marvels of computer engineering. They are robust, redundant, and most importantly, extremely powerful.  They have processing power for transactions unmatched by any current server architecture. Any bank with any sizable customer base has one, yes that’s right, every time you swipe a credit card (or buy something with it online), deposit a check, take out money at an ATM, that transaction makes it way to a mainframe which is locked away and guarded heavily somewhere deep within the confines of one of the banks operations centers.

How have they lasted so long? Well for starters they were damn expensive to buy, then software which was written on them was also expensive. So did IBM take the position of Apple and say, “sorry this new version just wont run that old cruddy COBOL transaction processor you wrote for 2 million dollars, you’ll have to rewrite it…” Of course not, they wrote their systems from the start with backward compatibility in mind, this means that mainframes that just rolled off the assembly line yesterday are fully capable of running that COBOL program written in 1973 with no performance degradation or negative side effects.

Oh yes, that’s right, those transactions form your 21st century online purchases are being handled by a 20th century COBOL program, shocking yea?

Now this backwards compatibility and amazing capability has come at a price, and that price is in ease of operation. A mainframe is nothing like a server, you need a team of highly trained individuals to use it, the mentality of operation is vastly different from that of server. You cant just sit in front of a mainframe terminal and log in and go on your merry way, you need to understand how it handles disk space, blocks, attributes, high level qualifier naming schemes and the list goes on.
In short anyone with a “For Dummies” Book and some common sense can administer a server, very few people with a whole stack of manuals and years of experience in normal IT can administer a mainframe, it is just that different.

If you are interested in learning more I have posted a few sites below with more information on mainframes as well a link to the IBM redbook repository online.

System Z – Z/OS – Mainframe specific books

Popular Redbooks – decent list of good red books

All Redbooks, System Z, Z/OS are trademarks of IBM Corporation and are linked here for information only, author claims no ownership or profit from these links whatsoever.