On RedHat Linux 6.2 I&#39;m running `free -m` and it shows nearly all `8GB` used

                 total       used       free     shared    buffers     cached
    Mem:          7989       7734        254          0         28       7128
    -/+ buffers/cache:        578       7411
    Swap:         4150          0       4150


But at the same time in `top -M` I cannot see any processes using all this memory:

    top - 16:03:34 up  4:10,  2 users,  load average: 0.08, 0.04, 0.01
    Tasks: 169 total,   1 running, 163 sleeping,   5 stopped,   0 zombie
    Cpu(s):  0.7%us,  0.3%sy,  0.0%ni, 98.6%id,  0.4%wa,  0.0%hi,  0.0%si,  0.0%st
    Mem:  7989.539M total, 7721.570M used,  267.969M free,   28.633M buffers
    Swap: 4150.992M total,    0.000k used, 4150.992M free, 7115.312M cached
    
      PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
     1863 sroot     20   0  398m  24m 9.8m S  0.3  0.3   3:12.87 App1
        1 sroot     20   0  2864 1392 1180 S  0.0  0.0   0:00.91 init
        2 sroot     20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd
        3 sroot     RT   0     0    0    0 S  0.0  0.0   0:00.07 migration/0
        4 sroot     20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0
        5 sroot     RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0
        6 sroot     RT   0     0    0    0 S  0.0  0.0   0:00.00 watchdog/0
        7 sroot     RT   0     0    0    0 S  0.0  0.0   0:00.08 migration/1
        8 sroot     RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/1



I also tried this [ps mem script][1] but it onlt shows about 400MB memory being used.


  [1]: http://www.pixelbeat.org/scripts/ps_mem.py

All Free Command Solutions on Gang of Coders

Total of 1 Free Command Solutions

Linux free shows high memory usage but top does not