Sean Carolan wrote:
> I'm monitoring some CentOS 5 servers running Sun Java. We have set
> things up so 2048 MB of RAM are available for the base operating system,
> taking into account the xMx and permgen settings. What we're seeing is
> the swap space getting used up, and not released. Is this normal
> behavior? Performance doesn't seem to be affected, however I'm a bit
> concerned that the swap file is completely full:
>
> free -m
> total used free shared buffers cached
> Mem: 9993 9945 48 0 174 1695
> -/+ buffers/cache: 8074 1919
> Swap: 2047 2033 14
>
> Here are the xMx and permgen settings:
> -Xms7177m -Xmx7177m -XX:MaxPermSize=768m
>
> Apart from Java/Tomcat/Apache and some HP hardware monitoring tools we
> are not running anything else on this server.
>
I think Xms/x is java's heap space for program object storage. It doesn't take
into account the space needed for the JVM itself. Top should show you the
actual memory usage - along with any other programs that might be using a lot.
--
Les Mikesell
lesmikesell at gmail.com