The following command displays terminal and disk activity five times, at five-second intervals: This information can be used to balance I/O loads. The output from the iostat command does not include disk request queues, but it shows which disks are busy. Use the iostat command to view terminal and disk activity, depending on the switches that you supply with the command.

Some paging always occurs even on systems with sufficient available memory. It is normal for the number of page-ins and page-outs to increase. The pi and po columns under the page column indicate the number of page-ins and page-outs per second, respectively. High scan rates are caused by a shortage of available memory. The sr column under the page column indicates the scan rate. Swap-ins and swap-outs should always be zero. The si and so columns under the page column indicate the number of swap-ins and swap-outs per second, respectively. If the value is not zero, then swapping occurs and the system is short of memory. The w sub column, under the procs column, shows the number of potential processes that have been swapped out and written to disk. The following is sample output of this command on HP-UX: Run one of the following commands to display a summary of CPU activity six times, at five-second intervals: Use the vmstat command to view process, virtual memory, disk, trap, and CPU activity, depending on the switches that you supply with the command. Refer to the vm_stat man page for more information about using this command. On Mac OS X, the vm_stat command displays virtual memory information.

Oracle database for mac os