on ubuntu precise, all apps starts slowly, and my hard drive is all time in use.

What is the cause? it was never before, even nautilus takes a lot time to load, boot is also slower.

top - 18:37:05 up  1:07,  1 user,  load average: 2.03, 2.34, 2.25
Tasks: 182 total,   1 running, 180 sleeping,   0 stopped,   1 zombie
Cpu(s): 30.2%us,  7.2%sy,  1.4%ni, 53.9%id,  7.1%wa,  0.0%hi,  0.2%si,  0.0%st
Mem:   3941576k total,  3522048k used,   419528k free,    50156k buffers
Swap:        0k total,        0k used,        0k free,  1827640k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND            
 2508 pk        20   0 1018m 189m  28m S    4  4.9  22:28.04 plugin-containe    
 1290 root      20   0 82336  16m 1492 S    2  0.4   0:04.41 landscape-clien    
 1305 root      20   0 97280  22m 5584 S    2  0.6   0:01.57 landscape-manag    
 4201 pk        20   0 17328 1312  924 R    2  0.0   0:00.02 top                
    1 root      20   0 24436 2364 1268 S    0  0.1   0:00.68 init               
    2 root      20   0     0    0    0 S    0  0.0   0:00.00 kthreadd           
    3 root      20   0     0    0    0 S    0  0.0   0:00.45 ksoftirqd/0        
    6 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/0        
    7 root      RT   0     0    0    0 S    0  0.0   0:00.02 watchdog/0         
    8 root      RT   0     0    0    0 S    0  0.0   0:00.00 migration/1        
   10 root      20   0     0    0    0 S    0  0.0   0:00.43 ksoftirqd/1        
   12 root      RT   0     0    0    0 S    0  0.0   0:00.01 watchdog/1         
   13 root       0 -20     0    0    0 S    0  0.0   0:00.00 cpuset