13 ms·

Powering a Mainframe

131 points by jandeboevrie 7y ago

6thaccount2 7y ago
I'd love to play with one as well and look forward to the later posts in this series. There has been a lot of mainframe related posts on HN lately.
- tyingq 7y ago
  You could download the Hercules emulator and either a very old legal copy of MVS, or a not-legal torrent of z/OS.
rvz 7y ago
I like seeing posts like this showing that there is still interest in operating with mainframes and bare-metal servers these days. My biggest fear is that you are in the minority of developers that can single-handedly operate one in the age of buzzword-ridden lingo such as AWS, GCP, Heroku, etc which forces a dogma to run rampant in our industry to host all of your startup/company only on other peoples's servers rather than to setup up your own in-house bare-metal servers instead. So I am very impressed to see this, as an added bonus it is a mainframe. Please post more of this.
- vbezhenar 7y ago
  It's not about clouds. The problem is with mainframe manufacturers. Their prices are ridiculous, so no sane man with limited budgets would buy it. I can build incredible powerful server from a desktop or workstation components for a few thousand dollars. Probably can reduce it to hundreds with using old parts. I can increase price to x2 and buy some HP or Dell blade and that would be real server hardware. But nobody is going to increase price to x100 and buy mainframe. That's just too much.
  - crb002 7y ago
    IBM is dead until it gets a mainframe in AWS region data centers. Mainframe is still king of CA in CAP.
    - znpy 7y ago
      Last time I checked IBM was alive and doing well.
      - jdsully 7y ago
        They’ve been in a 10+ year turnaround. “Doing well” is debatable.
  - coleca 7y ago
    Keep in mind that a lot of the people that are running mainframes now have been running them for many years (think 1980s), and there was no alternative that could run at the scale / speed / throughput that the mainframe can. So much of what we do today in the cloud can be attributed to the trails blazed by the mainframers. Fascinating technology.
- PinkMilkshake 7y ago
  > My biggest fear is that you are in the minority of developers that can single-handedly operate one You're right. About 6 months ago the University of Canberra, Australia started it's 'Bachelor of Information Technology in Mainframe Computing' degree program because of the shortage.
- WrtCdEvrydy 7y ago
  It won't last forever... I'm already hearing the term internally and within job postings -> 'repatriation'... bringing it back from AWS.
  - eecc 7y ago
    Yeah, it’s funny how much groupthink happens in businesses where you’d expect there to be purely rational decision making. There will be a tipping point where the groupthink will switch back to prioritizing in-house data centers.
- pjmlp 7y ago
  I am yet to do any major cloud deployment, most of our customers are very keen on having their data on their computers, not someone else's. So we did some small stuff on AWS and Azure and that was all about it, in max 5 years time the fad will be on the down path.
- eecc 7y ago
  The way I see it, cloud containers boil down to extending Java JEE like facilities to other stacks based on other languages. If you look hard enough at Kubernetes - perhaps with a Kafka queue in the mix - it will turn into a big Websphere cluster and wave back.
Lowkeyloki 7y ago
I looked at the author's previous post where he details the process of buying the thing. A fair amount of it goes over my head, I must admit. But that final price tag.... You've gotta really love mainframes. I can't imagine the utility bills for it. The power usage was reduced to 1.7kW. I guess some people buy a sports car and some buy a mainframe. Personally, I'd never be able to drop that kind of money for a hobby. I think emulating a mainframe on a fancy PC would scratch my itch. But to each their own.
- titanomachy 7y ago
  If you asked me how much I thought 700kg of computer should cost, I probably would have guessed more than $12k. Is this thing modern? Specs don't seem too impressive but I don't know anything about these things.
  - andrewcchen 7y ago
    In a previous post he said it's 8 years old
    - yjftsjthsd-h 7y ago
      I was about to think that was old, but then I remembered that mainframes, as I understand it, can aim for decade+ uptime, so that might actually be reasonably fresh?
idlewords 7y ago
This is a fascinating bit of nerdery. Would someone be willing to explain what mainframes are used for in a modern context, and how they compare to a really high-capacity x86 machine? I know that one difference is that you can hot-swap pretty much any component on a mainframe, but would be very curious to learn more about these beasts.
- vbezhenar 7y ago
  AFAIK they have incredible redundancy. Think about RAID-1 but for all components, so one CPU might fail and your software won't even notice that.
  - mikehollinger 7y ago
    It goes a bit deeper than that. I work on POWER which is a sibling to the z platform. They share some common architecture and microarchitectural elements. To get a sense, have a look at the E980’s Reliability, Availability, and Serviceability Manual. [1] that systems NOT a mainframe - but it borrows ideas from it. Even in that system all levels of it are designed for failure, from Customer replaceable units like fans or power supplies to certain busses have extra lanes or wires for parity or spares depending on the design. Internal to the processor logic there’s a large number of internal checkers that watch the architected state of the machine and notice when something abnormal happens. For several things the processor core will unwind its state and retry an op, and if it proceeds, flag itself as having had a “recoverable” error, which usually triggers a service action. If the system can’t recover it halts either the core or the entire platform, and a dump happens from the service processor which then offloads it to the management console for diagnosis. Z boxes do all of the above - and more. There’s pictures floating around the office of a system that went through and earthquake, fell over (someone didn’t buy the optional earthquake bracing for the rack) and as it fell, it domino’d over along with several other racks. It still running when the techs went to inspect the data center, though it did turn on its “service me” attention light. ;) [1] https://www.ibm.com/downloads/cas/2RJYYJML https://www.ibm.com/downloads/cas/2RJYYJML
- ofrzeta 7y ago
  "As late as 2017, IBM reported 92 of the top 100 banks still used mainframes for their core businesses." https://www.tpr.org/post/how-cobol-still-powers-global-economy-60-years-old https://www.tpr.org/post/how-cobol-still-powers-global-econo...
abraae 7y ago
I hate big power. When I was an IBM engineer, power into the computer room was a big deal. Big diesel generators feeding into the main switchboard along with redundant mains connections. One incident I remember is when an electrician was working on one of the power feeds while it was live. Foolish, but the kind of thing people did when getting approval to shut off power was a bureaucratic nightmare. The sparky was tightening down a bolt on one of the phases with a big crescent spanner when he inadvertantly made contact with another phase. There was a flash that lit up the room and a loud bang. His crescent spanner literally melted in the middle. Incredibly he was uninjured, although he did take the whole room down, which was an extremely serious matter. Modern computers that plug into the wall socket are much more pleasant to work on.
- C1sc0cat 7y ago
  Proper computing , I have heard similar war stories about telecoms accidents with large dc power systems and shorting the busbars. Real Datacentres have diverse routing for every thing
  - cr0sh 7y ago
    My senior year physics teacher in high school was a PhD student at Princeton who was doing teaching waiting to get back to his doctoral thesis research. Apparently, his work was with the Plasma Lab, primarily the Tokamak they had. Someone at some point had dropped a wrench or something on the bus bars of the capacitor bank used to power it - and, well, that was that. So he couldn't continue his studies until it was repaired. In the meantime, he taught us. Strange guy, but insanely intelligent, and fun to talk with. He always stressed the importance of "doing the experiment" - so we were always doing a practical experiments as a group to show how what we were shown and learned in class actually worked (within margins of error of course). I learned a ton in that class. After I graduated, I think he taught there one more year, then a few years later I looked him up, and he was back at Princeton, but was now working on something having to do with Materials science; I'm not sure what he's up to today, though - that was a couple decades ago. He wasn't much older than us at the time; late 20s or so.
- derefr 7y ago
C1sc0cat 7y ago
Interesting it runs straight off normal 3phase mains - the only mainframe I worked (a bit ) on was a small Unisys one and it had its own 400v supply as part of the set up.
- Merrill 7y ago
  The Z114 can be had with a power option to run off of 380-570 volts DC. See page 6 of "zEnterprise 114 System Overview" https://www-01.ibm.com/support/docview.wss?uid=isg2350bc7c39eab9a36852578ca00515918&aid=1 https://www-01.ibm.com/support/docview.wss?uid=isg2350bc7c39...
- blattimwind 7y ago
  400 V is normal 3 phase mains in about 85 % of the world, but whether consumers have 3 phases available or get 1 or 2 phases varies.
  - C1sc0cat 7y ago
    Ah yes I should have been specific I should have said a 400v DC.
- dfox 7y ago
  The Bulk Power Regulator mentioned in the blog post is essentially an 400V DC supply that powers everything else in the rack (including the blowers with threephase motors and their own DC/AC invertor). So it is similar except the power supply is built on modern power electronics and is quite small and internal in the rack.
  - magduf 7y ago
    >The Bulk Power Regulator mentioned in the blog post is essentially an 400V DC supply that powers everything else in the rack (including the blowers with threephase motors and their own DC/AC invertor). Any decent motor these days is a brushless DC motor, so it runs on DC voltage, except that it really doesn't. It gets DC voltage from a power supply (or it rectifies AC voltage to get DC, just like your computer's power supply), and then uses that to drive a motor drive (controller) (a box of electronics that runs the motor). The motor drive generates 3-phase AC power which is actually used to power the windings of the physical motor. The motor includes feedback devices which tell the controller the motor shaft's position so it knows where in the AC cycle the output waveform should be. There's always a lot of confusion about these motors because of this: they're called "brushless DC" (BLDC), but also 3-phase AC, and both are correct. The key is that the controller is really an integral part of the motor. It's similar to how your CPU probably runs on 1.8VDC, but you don't actually supply it that from your computer's power supply, the motherboard has its own voltage regulator to create that. You would never actually make a separate 1.8V power supply for a CPU, because it wouldn't work very well (high losses over distance); it's much more efficient to have the regulator closely coupled to the CPU.
derefr 7y ago
I’ve seen those “support element” laptops hanging off of racks before, but I always assumed that in this case (IBM mainframe, IBM support element, vertical integration) they were not laptops as such, but rather thin clients in the most literal sense: just IO interfaces with a ribbon cable feeding back to the mainframe, where the framebuffer of the mainframe’s dom0/maintenance VM was pushed over VGA and keyboard+mouse+peripherals were returned over USB. Essentially as if the support element were a Thunderbolt Display with USB HID devices plugged into it. Like a modern VT100! I’m honestly surprised to learn that I’m wrong, as having the laptop be a real laptop would introduce all sorts of headaches compared to having the laptop be a dumb terminal—it’d have active components like disks and fans that could to burn out (and not be hot-swappable like the server’s own components are); and more importantly, it’d have to talk to the server using some form of network interface (unless it’s just a glorified glass terminal for a USB-serial adapter.) In which case, bad behaviour on the server—exactly the case where you need a local admin console—could block or steal resources from your connection attempt. You may as well just be SSHing into the dom0 from across the room over the SBC VLAN at that point.
- dfox 7y ago
  Support element has to be more or less full-blown computer as the mainframe itself does not have any real firmware to boot^H^H^H^HIPL itself. Before support elements the IPL process involved initalizing various things by toggling switches on the console. Also why the mainframe would even have a framebuffer? Providing a console interface (ie. 3270 terminal emulator) to whatever OS runs on the mainframe is only small part of what SE does.
  - throw0101a 7y ago
    > real firmware to boot^H^H^H^HIPL itself. Have you considered using ^W?
    - dfox 7y ago
      No ^W in Emacs nor ISPF ;)
    - 7y ago
dsfyu404ed 7y ago
TL;DR put it where you want it and plug it into a 3-phase outlet.* *which slightly more complicated in Europe.
- magduf 7y ago
  Why? It shouldn't be. They use 3-phase in Europe just like in the US, for industrial locations. The differences in residential or lower-voltage standards really have nothing to do with industrial power availability.
  - dsfyu404ed 7y ago
    The author described some shenanigans he had to go through when wiring the power cord to get the power supplies (which expected voltage that is typical in the US) to run right. In the US it would have been a simple matter of using a power cord in the standard configuration and plugging it into the wall.
    - magduf 7y ago
      Looking closely at the photo of the power supply in the article, it looks like it's quite flexible and can handle different voltages, as long as they're 3-phase. It even lists different amp draws for the different voltage levels. In addition, it looks like it can handle 380-570V DC. With today's switching power supply technology, it's not hard to make them able to accept widely differing input voltages, so this is commonly done so you only need one part to cover the entire worldwide market. It looks to me like you can just plug this thing into any 3-phase power you want really. As for a "standard configuration" in the US, there really isn't such a thing for 3-phase power. There are a few NEMA standards used in industrial applications, but a lot of times, things like that are hard-wired. This isn't a home appliance.
infosecfriends 7y ago
If anyone is in Victoria, Australia and wants to play with an IBM z9 mainframe, i picked one up for about $500 and although I've managed to power and boot it, i haven't managed to load zOS on it properly. Got some time to spend on it and would love it if anyone else is interested in experimenting/getting it up and running. I also bought the relevant storage array (but no disks). Unfortunately that takes up a heap of space and I'm looking to offload it, it's free if anyone wants it, otherwise ill probably have to scrap it :( I usually lurk here but feel free to reach out via twitter (same username)
nimbius 7y ago
I was a former mechanical maintenance tech for an auto manufacturer, so this story feels familiar to connecting a CNC lathe, or a multi-axis mill, but reading this guys ham-fisted accounts made me pretty livid.. >The datacenter staff, not needing a forklift in their day-to-day, had managed to solicit the services of a forklift, the associated operator, and some very handy folks to help navigate the mainframe from the storage space to its final location. Since this thing can approach the cost of a rolls-royce,and weighs half as much as a prius, movers and millwrights should have been called in. watching two chubby guys in tennis shoes and no gloves move a 700 kilo server in reverse would have given me a heart attack. > The various guides did hint towards how the phases are connected to various Bulk Power Regulators (BPR) but nothing was very definite. that should have been your clue to hire an electrician. there is no such thing as a bulk power regulator. this is a BUCK POWER REGULATOR. >I tried to do my best to construct a power cable Make sure you tell your building supervisor and the fire brigade you "tried your best." there is no "tried your best" section in the electrical code. You either construct a cable to spec, or not. >Now, I assumed that given there is no neutral it has to be a delta system Since youre handling voltages that can kill you, perhaps a meter? >The uncertainty was which phase-pair powered the lowest BPR? I guessed A-B OR your BPR explodes, your HV breaker trips, and you wipe out power for half the building. Christ on his throne.
- racingmars 7y ago
  > there is no such thing as a bulk power regulator. this is a BUCK POWER REGULATOR No, in IBM mainframes, the rack component that takes the mains AC and starts doing something with it is, indeed, called a "bulk power regulator". For example, IBM part number 6186-7040, "Bulk Power Regulator". > that should have been your clue to hire an electrician Note in the article he did say "I confirmed the wiring scheme with some friends I have that do the power installations at Dreamhack, and even had them do the wiring as they have all the qualifications needed to do so safely and legally."

131 points by jandeboevrie 7y ago

I'd love to play with one as well and look forward to the later posts in this series. There has been a lot of mainframe related posts on HN lately.

tyingq 7y ago
You could download the Hercules emulator and either a very old legal copy of MVS, or a not-legal torrent of z/OS.

rvz 7y ago

I like seeing posts like this showing that there is still interest in operating with mainframes and bare-metal servers these days. My biggest fear is that you are in the minority of developers that can single-handedly operate one in the age of buzzword-ridden lingo such as AWS, GCP, Heroku, etc which forces a dogma to run rampant in our industry to host all of your startup/company only on other peoples's servers rather than to setup up your own in-house bare-metal servers instead. So I am very impressed to see this, as an added bonus it is a mainframe. Please post more of this.

vbezhenar 7y ago
It's not about clouds. The problem is with mainframe manufacturers. Their prices are ridiculous, so no sane man with limited budgets would buy it. I can build incredible powerful server from a desktop or workstation components for a few thousand dollars. Probably can reduce it to hundreds with using old parts. I can increase price to x2 and buy some HP or Dell blade and that would be real server hardware. But nobody is going to increase price to x100 and buy mainframe. That's just too much.
- crb002 7y ago
  IBM is dead until it gets a mainframe in AWS region data centers. Mainframe is still king of CA in CAP.
  - znpy 7y ago
    Last time I checked IBM was alive and doing well.
    - jdsully 7y ago
      They’ve been in a 10+ year turnaround. “Doing well” is debatable.
- coleca 7y ago
  Keep in mind that a lot of the people that are running mainframes now have been running them for many years (think 1980s), and there was no alternative that could run at the scale / speed / throughput that the mainframe can. So much of what we do today in the cloud can be attributed to the trails blazed by the mainframers. Fascinating technology.
PinkMilkshake 7y ago
> My biggest fear is that you are in the minority of developers that can single-handedly operate one You're right. About 6 months ago the University of Canberra, Australia started it's 'Bachelor of Information Technology in Mainframe Computing' degree program because of the shortage.
WrtCdEvrydy 7y ago
It won't last forever... I'm already hearing the term internally and within job postings -> 'repatriation'... bringing it back from AWS.
- eecc 7y ago
  Yeah, it’s funny how much groupthink happens in businesses where you’d expect there to be purely rational decision making. There will be a tipping point where the groupthink will switch back to prioritizing in-house data centers.
pjmlp 7y ago
I am yet to do any major cloud deployment, most of our customers are very keen on having their data on their computers, not someone else's. So we did some small stuff on AWS and Azure and that was all about it, in max 5 years time the fad will be on the down path.
eecc 7y ago
The way I see it, cloud containers boil down to extending Java JEE like facilities to other stacks based on other languages. If you look hard enough at Kubernetes - perhaps with a Kafka queue in the mix - it will turn into a big Websphere cluster and wave back.

Lowkeyloki 7y ago

I looked at the author's previous post where he details the process of buying the thing. A fair amount of it goes over my head, I must admit. But that final price tag.... You've gotta really love mainframes. I can't imagine the utility bills for it. The power usage was reduced to 1.7kW. I guess some people buy a sports car and some buy a mainframe. Personally, I'd never be able to drop that kind of money for a hobby. I think emulating a mainframe on a fancy PC would scratch my itch. But to each their own.

titanomachy 7y ago
If you asked me how much I thought 700kg of computer should cost, I probably would have guessed more than $12k. Is this thing modern? Specs don't seem too impressive but I don't know anything about these things.
- andrewcchen 7y ago
  In a previous post he said it's 8 years old
  - yjftsjthsd-h 7y ago
    I was about to think that was old, but then I remembered that mainframes, as I understand it, can aim for decade+ uptime, so that might actually be reasonably fresh?

idlewords 7y ago

This is a fascinating bit of nerdery. Would someone be willing to explain what mainframes are used for in a modern context, and how they compare to a really high-capacity x86 machine? I know that one difference is that you can hot-swap pretty much any component on a mainframe, but would be very curious to learn more about these beasts.

vbezhenar 7y ago
AFAIK they have incredible redundancy. Think about RAID-1 but for all components, so one CPU might fail and your software won't even notice that.
- mikehollinger 7y ago
  It goes a bit deeper than that. I work on POWER which is a sibling to the z platform. They share some common architecture and microarchitectural elements. To get a sense, have a look at the E980’s Reliability, Availability, and Serviceability Manual. [1] that systems NOT a mainframe - but it borrows ideas from it. Even in that system all levels of it are designed for failure, from Customer replaceable units like fans or power supplies to certain busses have extra lanes or wires for parity or spares depending on the design. Internal to the processor logic there’s a large number of internal checkers that watch the architected state of the machine and notice when something abnormal happens. For several things the processor core will unwind its state and retry an op, and if it proceeds, flag itself as having had a “recoverable” error, which usually triggers a service action. If the system can’t recover it halts either the core or the entire platform, and a dump happens from the service processor which then offloads it to the management console for diagnosis. Z boxes do all of the above - and more. There’s pictures floating around the office of a system that went through and earthquake, fell over (someone didn’t buy the optional earthquake bracing for the rack) and as it fell, it domino’d over along with several other racks. It still running when the techs went to inspect the data center, though it did turn on its “service me” attention light. ;) [1] https://www.ibm.com/downloads/cas/2RJYYJML https://www.ibm.com/downloads/cas/2RJYYJML
ofrzeta 7y ago
"As late as 2017, IBM reported 92 of the top 100 banks still used mainframes for their core businesses." https://www.tpr.org/post/how-cobol-still-powers-global-economy-60-years-old https://www.tpr.org/post/how-cobol-still-powers-global-econo...

abraae 7y ago

I hate big power. When I was an IBM engineer, power into the computer room was a big deal. Big diesel generators feeding into the main switchboard along with redundant mains connections. One incident I remember is when an electrician was working on one of the power feeds while it was live. Foolish, but the kind of thing people did when getting approval to shut off power was a bureaucratic nightmare. The sparky was tightening down a bolt on one of the phases with a big crescent spanner when he inadvertantly made contact with another phase. There was a flash that lit up the room and a loud bang. His crescent spanner literally melted in the middle. Incredibly he was uninjured, although he did take the whole room down, which was an extremely serious matter. Modern computers that plug into the wall socket are much more pleasant to work on.

C1sc0cat 7y ago
Proper computing , I have heard similar war stories about telecoms accidents with large dc power systems and shorting the busbars. Real Datacentres have diverse routing for every thing
- cr0sh 7y ago
  My senior year physics teacher in high school was a PhD student at Princeton who was doing teaching waiting to get back to his doctoral thesis research. Apparently, his work was with the Plasma Lab, primarily the Tokamak they had. Someone at some point had dropped a wrench or something on the bus bars of the capacitor bank used to power it - and, well, that was that. So he couldn't continue his studies until it was repaired. In the meantime, he taught us. Strange guy, but insanely intelligent, and fun to talk with. He always stressed the importance of "doing the experiment" - so we were always doing a practical experiments as a group to show how what we were shown and learned in class actually worked (within margins of error of course). I learned a ton in that class. After I graduated, I think he taught there one more year, then a few years later I looked him up, and he was back at Princeton, but was now working on something having to do with Materials science; I'm not sure what he's up to today, though - that was a couple decades ago. He wasn't much older than us at the time; late 20s or so.
derefr 7y ago

C1sc0cat 7y ago

Interesting it runs straight off normal 3phase mains - the only mainframe I worked (a bit ) on was a small Unisys one and it had its own 400v supply as part of the set up.

Merrill 7y ago
The Z114 can be had with a power option to run off of 380-570 volts DC. See page 6 of "zEnterprise 114 System Overview" https://www-01.ibm.com/support/docview.wss?uid=isg2350bc7c39eab9a36852578ca00515918&aid=1 https://www-01.ibm.com/support/docview.wss?uid=isg2350bc7c39...
blattimwind 7y ago
400 V is normal 3 phase mains in about 85 % of the world, but whether consumers have 3 phases available or get 1 or 2 phases varies.
- C1sc0cat 7y ago
  Ah yes I should have been specific I should have said a 400v DC.
dfox 7y ago
The Bulk Power Regulator mentioned in the blog post is essentially an 400V DC supply that powers everything else in the rack (including the blowers with threephase motors and their own DC/AC invertor). So it is similar except the power supply is built on modern power electronics and is quite small and internal in the rack.
- magduf 7y ago
  >The Bulk Power Regulator mentioned in the blog post is essentially an 400V DC supply that powers everything else in the rack (including the blowers with threephase motors and their own DC/AC invertor). Any decent motor these days is a brushless DC motor, so it runs on DC voltage, except that it really doesn't. It gets DC voltage from a power supply (or it rectifies AC voltage to get DC, just like your computer's power supply), and then uses that to drive a motor drive (controller) (a box of electronics that runs the motor). The motor drive generates 3-phase AC power which is actually used to power the windings of the physical motor. The motor includes feedback devices which tell the controller the motor shaft's position so it knows where in the AC cycle the output waveform should be. There's always a lot of confusion about these motors because of this: they're called "brushless DC" (BLDC), but also 3-phase AC, and both are correct. The key is that the controller is really an integral part of the motor. It's similar to how your CPU probably runs on 1.8VDC, but you don't actually supply it that from your computer's power supply, the motherboard has its own voltage regulator to create that. You would never actually make a separate 1.8V power supply for a CPU, because it wouldn't work very well (high losses over distance); it's much more efficient to have the regulator closely coupled to the CPU.

derefr 7y ago

I’ve seen those “support element” laptops hanging off of racks before, but I always assumed that in this case (IBM mainframe, IBM support element, vertical integration) they were not laptops as such, but rather thin clients in the most literal sense: just IO interfaces with a ribbon cable feeding back to the mainframe, where the framebuffer of the mainframe’s dom0/maintenance VM was pushed over VGA and keyboard+mouse+peripherals were returned over USB. Essentially as if the support element were a Thunderbolt Display with USB HID devices plugged into it. Like a modern VT100! I’m honestly surprised to learn that I’m wrong, as having the laptop be a real laptop would introduce all sorts of headaches compared to having the laptop be a dumb terminal—it’d have active components like disks and fans that could to burn out (and not be hot-swappable like the server’s own components are); and more importantly, it’d have to talk to the server using some form of network interface (unless it’s just a glorified glass terminal for a USB-serial adapter.) In which case, bad behaviour on the server—exactly the case where you need a local admin console—could block or steal resources from your connection attempt. You may as well just be SSHing into the dom0 from across the room over the SBC VLAN at that point.

dfox 7y ago
Support element has to be more or less full-blown computer as the mainframe itself does not have any real firmware to boot^H^H^H^HIPL itself. Before support elements the IPL process involved initalizing various things by toggling switches on the console. Also why the mainframe would even have a framebuffer? Providing a console interface (ie. 3270 terminal emulator) to whatever OS runs on the mainframe is only small part of what SE does.
- throw0101a 7y ago
  > real firmware to boot^H^H^H^HIPL itself. Have you considered using ^W?
  - dfox 7y ago
    No ^W in Emacs nor ISPF ;)
  - 7y ago

dsfyu404ed 7y ago

TL;DR put it where you want it and plug it into a 3-phase outlet.* *which slightly more complicated in Europe.

magduf 7y ago
Why? It shouldn't be. They use 3-phase in Europe just like in the US, for industrial locations. The differences in residential or lower-voltage standards really have nothing to do with industrial power availability.
- dsfyu404ed 7y ago
  The author described some shenanigans he had to go through when wiring the power cord to get the power supplies (which expected voltage that is typical in the US) to run right. In the US it would have been a simple matter of using a power cord in the standard configuration and plugging it into the wall.
  - magduf 7y ago
    Looking closely at the photo of the power supply in the article, it looks like it's quite flexible and can handle different voltages, as long as they're 3-phase. It even lists different amp draws for the different voltage levels. In addition, it looks like it can handle 380-570V DC. With today's switching power supply technology, it's not hard to make them able to accept widely differing input voltages, so this is commonly done so you only need one part to cover the entire worldwide market. It looks to me like you can just plug this thing into any 3-phase power you want really. As for a "standard configuration" in the US, there really isn't such a thing for 3-phase power. There are a few NEMA standards used in industrial applications, but a lot of times, things like that are hard-wired. This isn't a home appliance.

infosecfriends 7y ago

If anyone is in Victoria, Australia and wants to play with an IBM z9 mainframe, i picked one up for about $500 and although I've managed to power and boot it, i haven't managed to load zOS on it properly. Got some time to spend on it and would love it if anyone else is interested in experimenting/getting it up and running. I also bought the relevant storage array (but no disks). Unfortunately that takes up a heap of space and I'm looking to offload it, it's free if anyone wants it, otherwise ill probably have to scrap it :( I usually lurk here but feel free to reach out via twitter (same username)

nimbius 7y ago

I was a former mechanical maintenance tech for an auto manufacturer, so this story feels familiar to connecting a CNC lathe, or a multi-axis mill, but reading this guys ham-fisted accounts made me pretty livid.. >The datacenter staff, not needing a forklift in their day-to-day, had managed to solicit the services of a forklift, the associated operator, and some very handy folks to help navigate the mainframe from the storage space to its final location. Since this thing can approach the cost of a rolls-royce,and weighs half as much as a prius, movers and millwrights should have been called in. watching two chubby guys in tennis shoes and no gloves move a 700 kilo server in reverse would have given me a heart attack. > The various guides did hint towards how the phases are connected to various Bulk Power Regulators (BPR) but nothing was very definite. that should have been your clue to hire an electrician. there is no such thing as a bulk power regulator. this is a BUCK POWER REGULATOR. >I tried to do my best to construct a power cable Make sure you tell your building supervisor and the fire brigade you "tried your best." there is no "tried your best" section in the electrical code. You either construct a cable to spec, or not. >Now, I assumed that given there is no neutral it has to be a delta system Since youre handling voltages that can kill you, perhaps a meter? >The uncertainty was which phase-pair powered the lowest BPR? I guessed A-B OR your BPR explodes, your HV breaker trips, and you wipe out power for half the building. Christ on his throne.

racingmars 7y ago
> there is no such thing as a bulk power regulator. this is a BUCK POWER REGULATOR No, in IBM mainframes, the rack component that takes the mains AC and starts doing something with it is, indeed, called a "bulk power regulator". For example, IBM part number 6186-7040, "Bulk Power Regulator". > that should have been your clue to hire an electrician Note in the article he did say "I confirmed the wiring scheme with some friends I have that do the power installations at Dreamhack, and even had them do the wiring as they have all the qualifications needed to do so safely and legally."