Why is the memory usage reported by "ps" significantly different from that reported by "free"?
Issue
- The sum of the RSS values reported by
ps
is significantly lower than the amount of main memory used as reported byfree
.
For example:
$ ps aux | grep -v "USER" | awk 'BEGIN{sum=0}{sum+=$6}END{print sum}'
387056
$ free
total used free shared buffers cached
Mem: 2070740 1956740 114000 0 471584 863064
-/+ buffers/cache: 622092 1448648
Swap: 4192924 384 4192540
In this environment, the sum of RSS in ps is 387056kB. free shows used of -/+ buffers/cache is 622092kB. What is using the difference of 235036 kB?
- The total memory usage reported by
ps aux
is higher than the total physical memory.
Environment
- Red Hat Enterprise Linux, all versions
Subscriber exclusive content
A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.