Low Memory Ubuntu Install via F4

Raymii

http://erratasec.blogspot.co.uk/2013/03/ubuntu-low-mem-install-for-vms.html?m=1

Summary, when installing in XEN HVM/KVM, press F4 and select Low Memory.

djvdorp

Cool thanks

heiska

Since the link was yesterday on the front page of HN, I'll copy the top comments:

He made the two vms with different amounts of ram: the small one has 256M and the big one has 1G.
That's what the OS is supposed to do, fille a large portion of the unused and available memory with disk cache.

If you allocate more memory, programs will use it. Web browsers are notorious for abusing this, but it applies in lots of other places, including system cache.
In other words: if you allocate 1GB of RAM to a system and 256MB to another, the first will appear to use more RAM. You're reducing memory usage and performance at the same time. Whether you want that or not depends on what you want to run.

Memory analysis isn't right on this. real difference is:
561M - 487M(cached) - 23M(buffers) = 51M
vs.
50M - 21M(cached) - 6M(buffers) = 23M
2x difference (4M of which is vmtoolsd)

TL;DR: The author of "Advanced persistent cybersecurity" blog hasn't got a clue.