Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a Sony Vaio VPCZ122GX with 4GB RAM,Nvidia Cards. I install ubuntu 11.10 64 bit. I am currently open : 1 Tab Firefox, Virtual Box with 1 WinXP ~700 RAM, 1 terminal top. That's all. But Memory used is 3.5 GB. I think there must be memory leak while I can see in top: Virtualbox ( 2 process: 696MB + 37MB), Firefox 33MB. Can you help me to fix it. I try googling an searching in askubuntu but no luck.

enter image description here

share|improve this question
Can you post the output of free -m or a screenshot of top or how you are looking at your memory. – bodhi.zazen Jan 12 '12 at 4:20
Here is the screenshot of Top: – Summer Nguyen Jan 12 '12 at 4:56
Could it be RAM caching? – Dalton Miller Jan 12 '12 at 5:07
Yeah, may be that is right. I can see -/+ buffers/cache: 1442 2192 . It means 2192 GB RAM is currently Free. Thank you very much indeed. – Summer Nguyen Jan 12 '12 at 5:38
@DaltonMiller you should post that as an answer, and let Summer Nguyen accept it. This helps both of your reputations, and makes answers easier to find for new users. – Tom Brossman Jan 12 '12 at 8:55
up vote 7 down vote accepted

This is caused by Linux caching your RAM.

share|improve this answer
Please include some details from the link in your post as if the link were to stop working, your answer may not help future users. – hexafraction Sep 17 '12 at 22:39

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

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