You are correct. For successful Oracle implementations it is necessary to estimate the memory requirements, by considering SGA, PGA, number of dedicated connections, Linux page table requirements, ASM, RAC etc., The total of swap space and the guest memory relates to how much virtual memory is available for Linux to handle. If that is not enough for Linux then obviously will end up with out-of-memory limitations.
With System z Linux, it is advantageous to define multiple swap devices, with one or two smaller Virtual Disk (VDISK) as the primary or highest priority swap devices, and backed by another physical disk as the secondary swap device with lower priority. If you start seeing excessive swap used for the physical disk device, then it is time to investigate the workload, the Oracle memory settings and based on that the Linux Virtual memory size should be defined. If server is swapping a lot then performance will be bad and it is time to validate the memory requirements for the workload. Adding more swap space is just a solution to avoid any out-of-memory Linux pitfalls. Sam Amsavelu System z Linux Oracle Solutions Pre-sales Support, IBM ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
