Linux performance monitoring commands

uptime --The amount of time the system up and running
last --Log of system shutdowns and changes in run level
ps -flu oracle:  Processes are owned by the user oracle
pidof ora_arc0_LABDB1:  process identifier
free, cat /proc/meminfo
ipcs –m:  Shared memory segments on the system
ipcrm –M : delete shared memory segments by a user
pmap –x 2103 : details memory mapped by that particular process
ps -flu oracle | grep SCAN => cd /proc/7835 (is the scan process id)
oracle@si01.an.com{LABDB1}/proc/7835> cat status
ipcs –m
------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status     
0x68d7e0dc 17727490   oracle    660        4096       0       


/usr/sbin/lsof –u oracle | grep 17727490
slabtop (sort by u: memory,  


strace -p 26175 -o pmon_strace.txt
Process 26175 attached - interrupt to quit
Process 26175 dettached