Some UNIX Utilities for performance monitoring
vmstat command: vmstat is a command which can be use to display system statistics. Syntax is given below: vmstat <# second> < #number of times> Example vmstat 1 10 Above Command is to display the system statistics every second, 10 times. Sample Output of the command: vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 950888 57536 512868 0 0 559 45 479 671 9 2 73 15 Lets understand the column definition: Procs Column would be having three subcolumns r: count (processes waiting for run time) b: count( Processes in uninterruptible sleep) w: Count (Process which are swapped out and runnable) (on RHEL) If any process in b and w column then DBA/System admin has to check the system. Memory Column would be having following subcolumns: swap: swap space currently available.(in kBs) free: Amount of idle memory(kBs) buff: Memory