migrating Moodle instances from Azure VMs to AWS EC2 VMs

Just a few days after we upgraded Moodle from 4.5 to 5.3 as in this earlier post, we had to migrate from Azure to AWS. To try out how good it would be, I prompted Claude.ai to first give me an appropriate configuration, then to step by step carry out the migration. I'll document what I did in a series of posts instead of as a single post, with this post linking to all the series.

Initial idea was to use a single ARM EC2 instance, since that is the cheapest. But found that in the Mumbai zone of Asia-Pacific region, the price difference between ARM and x86_64 was not significant, and also ARM was capacity constrained there. So, went with t3.large (burstable, two vcpus, 8 GB RAM) and an attached data disk instead of the possibly cheaper S3 storage.

But before that, I'd explored feasibility of using ARM cpus - 

confirm if our custom CMS has no x86-only binaries or PHP extensions (TODO separate post).

More to come below....