DISCLAIMER: This is a continuing series detailing the painful story of a DIY render farm build. It is terribly technics and
somewhat frustrating. Those who are unprepared for such “entertainment” are advised to ignore these posts.
I have the PDC working, and I had turned my attention to the worker units – old Mac Pro 1,1s with 10Gb of RAM and only supported up to Mac OSX 10.7.
MLPF (Mountain Lion Post Factor, the OSX Hacking tool that lets you install 10.8 Mountain Lion on unsupported, old machines) only works with the.app version of the Mountain Lion installer – that’s the one that comes directly from the online Mac Store. I think they did that to dodge copyright issues and make the tool only useful for people who have an original authorized copy of the operating system, rather than a pirate version. 10.8 was still a pay version, I think.
For me this means spending $20 on an Apple download of 10.8 just to find out if MLPF works on these machines. Which it could not. Testing Open Source stuff on machines and then throwing it out is one thing, but this seems much risker. This is very much against my policy of not spending any money. If I could throw away $20 on something I’m not even remotely sure would work, then I’d probably not be doing a lot of this stuff. It’s a bit depressing.
As it turns out, 10.8 is one of those operating systems I skipped entirely. At home I went directly from 10.6.8 right to 10.9 Mavericks. So I never had a copy of 10.8 because I never used Mountain Lion. If I had bothered to upgrade everything when I “should” have, I would have that file sitting around on my own personal backups. So I’m wondering how I’m going to do this.
In the meantime, in an effort to fake out MLPF, I have copied a 10.8 ESD image (which can be found on Apple.com) inside an old 10.7 installer.app, thinking that the .app part was probably just a wrapper. If MLPF found all the resources it needed, it might have installed.
Sadly, this did not fool MLPF, and it failed.
Thus I came up with the great idea to open MLPF and attempt to run the install packages for the software by bypassing the check. This resulted in an install, but also kernel panics once I restarted.
What a mess.
Having wrecked the system, I reinstalled 10.7 . With every reinstall, I also had to run the 10.7 combo update and X11 update. This took some time. When I ran MLPF it would take all of two seconds to destroy the fresh 10.7 install that took a couple hours to prepare.
So while I waited, I read the fine print on MLPF, which told me it was not supported on the Mac Pro 1.1, which, of course, is all I had. But “not supported” means a lot of things on a program that’s designed to make software that’s not supported work on certain machines that are not supported. Is that like a double negative? I had to try it anyway.
In the meantime, I got ready to deal with Dr. Queue on the slave machines. I did not know how easy it would be to build on the Intel architecture, but anything had to be better than that PPC version. I only needed the command line slave program, and no front end of any kind. So there really was no reason to worry about an X11 update or any of the GTK worries I had with the PPC version. I could ditch everything else, because the slave machines need only to run a tiny command-line program that executes even smaller shell script commands sent to it. The heavy-lifting would be done by the render programs themselves.
Thus the slaves are in a state of permanent listening, standing at attention and waiting for a command. The master sends the commands and those are automatically executed.
Hours later, I was still puzzling over the operating system. Using 10.8 or even 10.9 would mean that I could run After Effects CC 2014 and not just the previous CC version. I don’t know how useful a render farm is if I have to take any job going into it and downgrade it before sending. Or worse yet, to be stuck on old software and not be able to update ever again. That seemed like a lot of “pre-flight” work.
That’s when I saw that the same clever kids that worked out MLPF were now making promises of Mavericks (10.9) on older models. Skipping 10.8 and going right to 10.9 does mean the farm is good for longer… The MLPF guys were even promising 10.10 Yosemite, the absolute latest operating system. People posting on the MLPF project page were taking old MacBooks normally considered out of date doorstops and running the latest on them. They ran kind of slowly, with a few goofs, but they were still running. And therefore still useful for lots of tasks.
I don’t want the newest bells and whistles on these machines. The render farm will run command line versions of all the software it uses, even After Effects. I did not need “Maps” to work, and could not care less if the cool transparency effects were working well. There would be no “FaceTime” on these machines. The new version, now called simply “Mac Post Factor,” seemed to be just the trick.