Red Hat Linux introduced a change in glib 2.11 that creates larger per-thread address spaces aligned at 64MB. This change results in a virtual process size much larger than those seen in previous versions of glibc. This is not considered a bug by RedHat, as noted in https://bugzilla.redhat.com/show_bug.cgi?id=640286, and does not affect the physical memory needed by the server process. To see the version of glibc on your system, use the command yum info glibc.