Unfortunately with Pub400 free account you only get user level access, so useful for learning the basics of using the system and developing code for it, but not for understanding the internals (topic of this blog post), you need sysadmin level access for that.
You can get a dedicated instance with sysadmin level access if you pay either Pub400, IBM, or a few other vendors. (The smaller instances are not bare metal, they are actually VMs using IBM’s hypervisor.) Whichever way you go you are paying $$$$, because IBM’s licensing for the OS starts at thousands of dollars a year (even for a very low-end system), and gets bigger quickly as the CPU/memory grows.
Alternatively, if your goal is non-production exploration of low-level details of the system as described in this article, or even just learning the ropes of IBM i, another option is to buy an old POWER6 or POWER7 system on eBay that's licensed for virtualization and a reasonably recent version of the base IBM i OS, then use it to create disposable evaluation VMs running whatever additional extra-cost software you want to play with (time-limited evaluation copies of most first-party IBM i software are freely downloadable from IBM's Web site).
While these systems won't run anything newer than IBM i V7R2 (POWER6) or V7R3 (POWER7), they're likely to be both faster and cheaper than inexpensive cloud options.
Consider:
In 2017, I paid $1,700 for a POWER6 server (2 CPU cores, 16 GB RAM, half a dozen 137 GB hard drives) with virtualization and IBM i licenses.
The cost estimator on IBM's Power Virtual Server site suggests that their cheapest VM capable of running any version of IBM i they support (0.25 CPU cores, 2 GB RAM, 35 GB storage) costs around $400/month.
> The cost estimator on IBM's Power Virtual Server site suggests that their cheapest VM capable of running any version of IBM i they support (0.25 CPU cores, 2 GB RAM, 35 GB storage) costs around $400/month.
RZKH (who run Pub400), the cheapest they charge is 245 EUR/month, which at current exchange rates is about US$263/month. That's 0.05 CPU cores, 2 GB RAM, 100 GB storage), without development tools. Development tools license is additional EUR 79/month (about US$85/month) per concurrent user. Plus they want a minimum 4 month commitment, so it is over US$1000 anyway. At which point, yes your eBay option looks better, unless you really need the latest OS
You can get a dedicated instance with sysadmin level access if you pay either Pub400, IBM, or a few other vendors. (The smaller instances are not bare metal, they are actually VMs using IBM’s hypervisor.) Whichever way you go you are paying $$$$, because IBM’s licensing for the OS starts at thousands of dollars a year (even for a very low-end system), and gets bigger quickly as the CPU/memory grows.