Hi, I have two 64 bit cent Os machine. I googled that in linux always show entire memory as used. But below showing only 1 GB detected. *Machine 1 :* i) It has 31 GB of ram. [root at machine1]# free -g total used free shared buffers cached Mem: 31 1 30 0 0 0 -/+ buffers/cache: 0 30 Swap: 49 0 49 ------------------------------------------ *Machine 2 :* i)It has 11 GB of ram. [root at machine2]# free -g total used free shared buffers cached Mem: 11 11 0 0 0 9 -/+ buffers/cache: 1 10 Swap: 49 0 49 Could you please anyone can explain why ? Thanks, Ashik -* *