Problem :
Here a output of “free -m” from my machine, I don’t know if this means that RAM is low:
root@mymachine:~# free -m
total used free shared buffers cached
Mem: 4048 3929 118 0 4 661
-/+ buffers/cache: 3263 784
Swap: 255 100 155
Also I added below output of top “command”:
top - 10:05:10 up 2:46, 1 user, load average: 1.76, 1.83, 1.76
Tasks: 80 total, 1 running, 79 sleeping, 0 stopped, 0 zombie
Cpu(s): 16.1%us, 4.0%sy, 0.0%ni, 51.9%id, 2.8%wa, 0.0%hi, 0.8%si, 24.4%st
Mem: 4145552k total, 4025128k used, 120424k free, 4812k buffers
Swap: 262140k total, 113196k used, 148944k free, 688328k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3904 root 20 0 2452m 2.1g 3964 S 111 53.9 56:31.72 java
1999 mysql 20 0 170m 33m 2660 S 76 0.8 36:14.09 mysqld
2420 root 20 0 2439m 944m 3636 S 1 23.3 8:02.11 java
9716 root 20 0 2464 1068 828 R 1 0.0 0:00.03 top
Solution :
Firstly the definition of low is somewhat subjective, it depends on what else you may intend to run.
An important point to bear in mind when viewing the output of free is that the first line includes all the buffered content (which is imediately discarded if more memory is needed), this means that you should look at the second line to find the ‘actual’ free memory. In this case it’s 784 MB (~20% of your total).
As mentioned your swap space is quite small compared to your ram, while the old advice of 2 times physical ram for swap size is not really needed now, I think you’d be better off with a larger swap space, particulary since you’re not so far off maxing out your ram.
The real answer to your question is that it depends on the situation!