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pdardeau

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Undeveloped Film from a Soldier in WWII Discovered and Processed 12 years ago

Digital photography just doesn't have the soul of actual film photography it's missing the physical connection.

Indeed! I just recently bought a couple of old 35mm SLR bodies and lenses to get back into film photography. With film, photography is certainly more deliberate and slower-paced. I also enjoyed darkroom work (years ago) as much, if not more, than taking photos. The darkroom was a nice, quiet place that was very relaxing.

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IBM Launches Z13 Mainframe 12 years ago

the [Power/AIX] virtualization is insanely good in practice

This is my experience as well. IMO, Power/AIX has the most sophisticated virtualization available. IBM just has no idea how to market it.

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IBM Launches Z13 Mainframe 12 years ago

You're regurgitating 'common' wisdom here, but you really should check your assumptions and reality when it comes to current mainframes. IBM's mainframes have a minimum and maximum number of engines (CPU). An engine can be either general purpose (I forget the acronym they use) for use with z/OS, or can be a specialty engine (IFL, zIIP, zAAP). My understanding is that it's the same hardware, just a simple firmware update to tell the engine what 'type' it is. An IFL (what you would use to run Linux under z/VM) is significantly cheaper than the general purpose one used for z/OS. Also, mainframes can be loaded with more engines that what you've paid for -- this is what IBM calls Capacity-On-Demand (COD). So you can temporarily activate additional engines to handle spikes. The zSeries has some fantastic capabilities for Reliability, Availability, and Serviceability (RAS). The systems I've been around keep engine utilizations quite high (98/99%) as the norm.

A mainframe is typically partitioned into multiple, smaller systems. This is what IBM calls a Logical Partition (LPAR). This partitioning is done with firmware called PR/SM. This capability has been around since the 3090 (mid to late 80's). Within an LPAR, one typically installs either z/OS or z/VM (there are other systems too, but less commonly used this way). Running in an LPAR is 'bare metal'. Within z/VM, there's typically a mix of guest types, but this is where Linux would typically be configured to run. z/VM has some pretty impressive capabilities and has been around for a LONG time. It's very stable. The biggest things that you would probably dislike about it are: (1) one uses a 3270 emulator to do day-to-day system-level admin work, (2) it only runs (legally) on real mainframe hardware, and (3) much of IBM's jargon is dated and would unfamiliar to people coming from x86.

The modern mainframe hardware and software has an impressive feature set for virtualized networking (networking is all software defined and runs within the box). This means you can set up hundreds or thousands of Linux guests and have them on networks that are all virtualized within z/VM. And of course, z/VM guests can be created and spun-up on demand and stopped on-demand. This has been there for decades.

IBM now has support for OpenStack in z/VM. From what I've perused, it seems to be quite slick. Assuming it all works as advertised, this would make folks coming from x86 feel much more at home.

Many seem to think that distributed systems are so much cheaper. You can't just think of it as the price of the rack server though. You have to include everything in the mix to understand the total cost: hardware, software, networking, people (headcount and consulting), power and cooling, floorspace, and intangibles (such as capabilities). When you do the math, mainframes running Linux under z/VM are often fairly economical (YMMV).

Once you throw off the stereotypes and objectively dig into the modern mainframe, you might be surprised at what you find.

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