Just installed 64-bit Ubuntu Server 10.10 inside as guest in a virtual machine. I'm using VMware Player. The host is 64-bit Windows 7.

The minimum requirements for the Ubuntu server is said to be 128MB RAM. https://help.ubuntu.com/community/Installation/SystemRequirements

So right after the install, I ran top command and to my surprise it said:

Tasks: 63 total, 1 running, 62 sleeping, 0 stopped, 0 zombie
Mem: 504088k total, 446192k used, 57896k free, 30548k buffers

From what I've read, modern Linux systems buffer memory for performance reasons. But here, only ~30.5MB is used for buffers.

I sorted based on %MEM and there's nothing that stands out (biggest hogger is at 1.3%). Is it because of the virtualization that the memory is some how pre-allocated and thus shown in the used field?


free -m
          total      used      free     shared     buffers     cached
Mem:        492       435        56          0          29        338
-/+ buffers/cache:     67       424
Swap:       563         0       563
  • 3
    What does free -m say? – Cakemox Oct 15 '10 at 13:58

From your free output, you're only using 67MB. The rest is used for buffers (29M) and filesystem cache (338MB).


Check out this page - it'll give you a better understanding of what's most likely going on:

Linux Ate My RAM!

  • Very concise link.. exactly to the point. I gave you an upvote, but will accept Cakemox's answer. Thanks! – randomguy Oct 15 '10 at 14:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.