Hello, thanks for the explanation. Tried a 2GB data segment limit. Did not make any difference. Limit Soft Limit Hard Limit Units Max data size 2147483648 2147483648 bytes Max address space unlimited unlimited bytes Right after startup: Name: mserver5 State: S (sleeping) VmPeak: 143976 kB VmSize: 143972 kB VmLck: 0 kB VmHWM: 31616 kB VmRSS: 31612 kB VmData: 35300 kB VmStk: 88 kB VmExe: 16 kB VmLib: 27244 kB VmPTE: 280 kB Threads: 4 During query: Name: mserver5 State: S (sleeping) VmPeak: 34989088 kB VmSize: 33975968 kB VmLck: 0 kB VmHWM: 22337400 kB VmRSS: 21633720 kB VmData: 335008 kB VmStk: 88 kB VmExe: 16 kB VmLib: 27244 kB VmPTE: 49828 kB Threads: 21 After query: Name: mserver5 State: S (sleeping) VmPeak: 34989088 kB VmSize: 26377504 kB VmLck: 0 kB VmHWM: 23093936 kB VmRSS: 20414060 kB VmData: 335008 kB VmStk: 88 kB VmExe: 16 kB VmLib: 27244 kB VmPTE: 48876 kB Threads: 20 What about this constant factor of 0.815 in gdk/gdk_utils.c. Could lowering that help? 1201 /* Mserver by default takes 80% of all memory as a default */ 1202 GDK_mem_maxsize = GDK_mem_maxsize_max = (size_t) ((double) MT_npages() * (double) MT_pagesize() * 0.815); Regards, Christian.