=====Process Checking===== ===Output Detailed Process Tree for any User=== An easy function to get a process tree listing (very detailed) for all the processes of any gived user. # psu(){ command ps -Hcl -F S f -u ${1:-$USER}; } # psu uadmin F S UID PID PPID CLS PRI ADDR SZ WCHAN RSS PSR STIME TTY TIME CMD 5 S uadmin 23028 23026 TS 18 - 2481 - 1600 0 08:04 ? 0:00 sshd: uadmin@pts/0 0 S uadmin 23029 23028 TS 20 - 1168 - 1464 0 08:04 pts/0 0:01 \_ -bash ===Show processes causing high load average=== Want to know why your load average is so high? Run this command to see what processes are on the run queue. Runnable processes have a status of "R", and commands waiting on I/O have a status of "D". # ps -eo stat,pid,user,command | egrep "^STAT|^D|^R" ===Which program does a port belongs to?=== Sometimes you need to use a port that is already opened by some program , and you don't know who to "kill" for it to release - so, now you do ! # lsof -i tcp:22 # lsof -i tcp:80 ===dstat=== dstat - a mix of vmstat, iostat, netstat, ps, sar... # dstat -ta ===vmstat with timestamp=== vmstat/iostat with timestamp. Also useful with iostat, or pretty much anything else you want timestamped. # vmstat 1 | awk '{now=strftime("%Y-%m-%d %T "); print now $0}'