mainframe.dev

My earlier blog article named Buying an IBM mainframe  did get way more exposure than I could have hoped for, thanks to everyone that read it! The discussions on various forums did naturally evoke some interesting questions. Mostly they are "Why?" in various shapes or forms. It is a totally understandable reaction, and thus I want to present some of the things that I am excited about having mainframes as a hobby. I present to you: the follow up questions on the statement "I bought an IBM mainframe". Why? I thought mainframes were dead First of all, they are not. If you are buying a new mainframe today you will get a beast in terms of performance and especially I/O capability. There is no server platform that compare to my knowledge in pure numbers if you do not include cost. Of course, you would care deeply about cost in any real-life situation but the point is to dispel the notion that mainframes are antiquated technology wise. Even my 8 year old z114 can...

IBM System z supports a handful of operating systems; z/VM, z/VSE, z/OS, z/TPF, and finally zLinux. All the earlier mentioned OSes are proprietary except for zLinux which is simply Linux with a fancy z in the name. zLinux is the term used to describe a Linux distribution compiled for S390 (31 bit) or S390X (64 bit). As we are talking about modern mainframes I will not be discussing S390, only S390X. There is a comfortable amount of distributions that support S390X - more or less all of the popular distributions do. In this  list  we find distributions like Debian, Ubuntu, Gentoo, Fedora, and RHEL. Noticeably Arch is missing but then again they only have an official port for x86-64. This is great - this means that we could download the latest Ubuntu, boot the DVD, and be up and running in no time, right? Well, sadly no. The devil is, as always, in the details. When compiling high level code like C/C++/Go the compiler needs to select an instruction set to use for the compi...

I bought an IBM mainframe for personal use. I am doing this for learning and figuring out how it works. If you are curious about what goes into this process, I hope this post will interest you. I am not the first one by far to do something like this. There are some people on the internet that I know have their own personal mainframes, and I have drawn inspiration from each and every one of them. You should follow them if you are interested in these things: @connorkrukosky @sebastian_wind @faultywarrior @kevinbowling1 This post is about buying an IBM z114 mainframe (picture 1) but should translate well to any of the IBM mainframes from z9 to z14. Picture 1: An IBM z114 mainframe in all its glory Source: IBM What to expect of the process Buying a mainframe takes time. I never spent so much time on a purchase before. In fact - I purchased my first apartment with probably less planning and research. Compared to buying an apartment you have no guard rails. You are ...

I've been learning about z/OS and MVS over the last couple of weeks using the Master the Mainframe course and also the highly affordable courses from Interskill. I wanted to build something proper so I built a thing that can backup a full z/OS system to CCKD files (same as what Hercules/Hyperion uses). With the fixes for 64-bit CCKD to Hyperion now merged, and the 64-bit cckddump tooling appears to be in progress, this might come in handy for some folks. This is the CCKDALL JCL: //CCKDALL JOB 1,NOTIFY=&SYSUID //DUMPJCL SET DUMPJCL=&&SYSUID..JCL(CCKDDUMP) //DASDS EXEC PGM=SDSF //ISFOUT DD SYSOUT=* //CMDOUT DD DSN=&&SDSF,DISP=(NEW,PASS,DELETE),SPACE=(CYL,1), // RECFM=FB,LRECL=100 //ISFIN DD * SET CONSOLE BATCH SET DELAY 2 /D U,DASD,,,9999 PRINT FILE CMDOUT ULOG PRINT PRINT CLOSE //* //FMT EXEC PGM=ICETOOL //TOOLMSG DD //DFSMSG DD SYSOUT=* //IN DD DSN=&&SDSF,DISP=(OLD,DELETE,DELETE) //OUT D...

Introduction The Leopard is an OpenRack v1 compliant 12V server commissioned by Facebook to offer compute power. It consists of 2x Intel Xeon E5-2678 v3 and is available with either DDR3 or DDR4 memory. The model is manufactured by two vendors primarily: Quanta and Wiwynn. Leopard features a 24x PCIe slot which can fit either a PCIe card with low profile, or a riser card with 1x 16x and 1x 8x slots. The server also supports a 3.5" SATA drive as well as either an mSATA or an M.2 drive mounted on the motherboard. Connectivity wise Leopard has a mezzanine card slot allowing for example 10Gb/s or 25Gb/s Ethernet. Figure 1: Wiwynn Leopard DDR4 from the front Source: Wiwynn OCP design package Figure 2: Wiwynn Leopard DDR4 from above Source: Wiwynn OCP design package Figure 1 and figure 2 shows the server layout. The server is made to fit inside an OpenRack v1 enclosure, at which point it looks something like figure 3. Due to power constraints an OpenRack v1 can fit ...

Let's say that you are a system administrator in a decently sized company. You're responsible for selecting new servers for a pretty decently sized upgrade round in your data centers, or maybe you're building a new datacenter. It's not that long ago this happened last time for your company, but since we're living in an ever-changing world things of course are complicated. What do you do? Let's look at your options. Go with the same vendor and same models as you did previously. Safe bet, will not get you fired even if it's the least cost effective solution. Probably will not get you promoted either though, and the pains of today will be the pains of tomorrow. Look around for new vendors. Maybe you're finally looking at Supermicro instead of only doing HPE, or the other way around. Risks are higher, but all those issues with iDRAC/iLO/IPMI are surely fixed on the other vendor - right? This is the world I remember living in when I worked for a small I...