Network traffic for an Ironic Node

I’ve set up a second cluster, and the Ironic nodes are not PXE booting. Specifically, if I watch the nodes boot via an IPMI serial-on-lan console, I see that they send out a DHCP request and never get a response back.

This is a problem I am familiar with from my days at Penguin. Time to dig in and understand the networking setup on the controller to see why it is not getting the packet. Or, possibly, why it is getting it and the response is getting dropped.

I have another cluster that is working properly, and I am going to look at the setup there to try and contrast it with the broken set up, and figure out my problem.

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Multiplication by Halving and Doubling in AARCH64 Assembly

While multiplication is defined in the context of repeated addition, implementing it that way algorithmically is not nearly as efficient as some other approaches. One algorithm for multiplication that is an order of magnitude faster is to halve one number while doubling the other. I gave myself the challenge of implementing this algorithm in AARCH64 Assembly, and it was not too hard.

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Understanding the MIXAL insertion sort.

A debugger is a wonderful tool for understanding what actually happens in a piece of code. Donald Knuth’s coding in TAOCP is archaic enough that I do not understand it just by reading through. This is due to a combination of my unfamiliarity with MIXAL, as well as some of the coding conventions he’s chosen. So, I’m going to step through the MIXAL code in mixvm, and annotate what I find.

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