實用的Linux命令

//每2秒檢查1次，檢查10次
root@cnpphttp50:~# top -d 2 -n 10

//顯示現在登陸著的使用者，load:5/10/15 mins
root@cnpphttp50:~# w
 11:29:08 up 231 days, 10:44,  1 user,  load average: 0.00, 0.00, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
fzou     pts/0    10.5.46.180      11:25    0.00s  0.07s  0.00s sshd: fzou [priv]

//顯示使用者的組
-bash-3.2$ groups mqm
mqm : mqm asinstall bconsole GR-MQM-ADM
[ora10gas@rtdkm1jcx01 ~]$ groups ora10gas
ora10gas : asinstall bconsole mqm

//檢視開啟埠的程式
sudo lsof -i : 

//check are there any network issue at that time
netstat -i

//Force changed blocks to disk, update the super block. Makes sure we avoid data corruption
Flush Buffers to Disk:
gpssh -f /home/gpadmin/gpconfigs/hostfile sync