[CentOS] 2.6 memory management question

[Feizhou]

>> [2]$ cat /proc/meminfo
>> MemTotal:      7128956 kB
>> MemFree:       2132556 kB
>> Buffers:        556832 kB
>> Cached:        2821408 kB
> 
> A supplementary question, can anyone explain what "buffers" and "cached" 
> are? I have a performance problem with postgresql (discussion is on the 
> postgresql list), and I see those figures displayed by commands such as 
> free, top and procinfo but the man pages don't define them.
> 
> 
> 

Buffers = disk buffers (buffers of stuff to be read/written)
Cached = page cache which stores filesystem and process pages...copy of 
files in memory