Comment by evgpbfhnr
>> You definitely can use Linux with few simple servers with 128 MB RAM. > > This is not difficult, you just need to run `htop` and perform addition of the RES column (which is in KB unless a unit is shown). Example:
I'm not quite sure what points this makes... That's supposed to fit on 128MB? And it doesn't include memory consumed by the kernel itself (which is not negligible at this scale), and linux needs spare for cache to work remotely decently.
$ awk '{ tot+=$2 } END { print tot /1024 }' < list
214.035
The point was that most of the shown software is optional, and you can check how much selecting those parts you care about sum up to.
To provide "conclusive proof" that it's possible to run a 128 MB Linux system.
For example, if you remove (or configure smaller memory use for) journald, the Amazon daemon, oomd, timesyncd, you are already at around 128 MB userspace, with more that can be removed if desired.
And this is on a distro that is not at all designed to be minimal in memory usage.
How much cache is good depends entirely on what you want the system to do.