Does my Centos server leak memory?

Solution 1:

You have enough memory. You would have problem with memory if your used memory rizes to max amount and buffers and cached will be very low, using of SWAP will rize then you probably will have problems with free RAM. From your post it's everything ok....

This is simple explanation what commited memory is:

Committed_AS: An estimate of how much RAM you would need to make a 99.99% guarantee that there never is OOM (out of memory) for this workload. Normally the kernel will overcommit memory. That means, say you do a 1GB malloc, nothing happens, really. Only when you start USING that malloc memory you will get real memory on demand, and just as much as you use. So you sort of take a mortgage and hope the bank doesn't go bust. Other cases might include when you mmap a file that's shared only when you write to it and you get a private copy of that data. While it normally is shared between processes. The Committed_AS is a guesstimate of how much RAM/swap you would need worst-case.

Here is hole explanation http://www.redhat.com/advice/tips/meminfo.html

So you don't have problems with memory everythings is ok those readings are normal.

Solution 2:

There is a shared memory usage with your apache model, this is fine. ps/top won't show you exact usage, that's not an easy task. Try http://www.pixelbeat.org/scripts/ps_mem.py