Most people that I know of can’t afford, or do not wish to spend much on hardware. However, in case of EBS 12.2, there is a bare minimum that is needed for you to be able to do online patching etc. live on your lab instance. Here is what I recommend.
A laptop or desktop with the following spec:
Quad Core or Higher CPU (Intel/AMD)
16 GB RAM
500 GB Free Space in HDD
Let me explain why we need this as a bare minimum:
CPU: We will be using VirtualBox, a type 2 hypervisor for this lab. This is a software that will run on your windows machine and will enable you to create Linux guest VM inside windows. If you have a dual core system, you can only assign one core to the VM, if you assign more, your host machine (laptop) will suffer and you’ll get frustrated. Note that some steps are CPU bound, like adutlrecomp, and even a 2 core VM will take over 5 hours to run it. Trust me, I’ve been there.
RAM: In my experience, for online patching to work, you will a minimum of 10 GB RAM for the application node. The DB will need 2 GB. so you need a minimum of 12 GB for the VM. Assuming that you will have Google Chorme running on the host with multiple tabs open (a big memory hog) it’s safe to set aside 3 GB for the host OS.
HDD: This one is straightforward. 15GB for OS+, 12GB of swap, 290 GB of post install application, ~50 GB of stage. During online patching we also need additional space for the ADOP tasks. 500 GB will serve us well, while providing a little bit of wiggle room.