Useful UNIX Commands For Oracle DBAs

Basic knowledge in UNIX is very essential for any DBA.

Given below are some few useful UNIX commands for Oracle DBAs in their daily work.

1.  To Cleanup trace files more than n days old

$ find $DBA/$ORACLE_SID/bdump/*.trc -mtime +n -exec rm {} \;

2. To get the value of all environment variables.

$ env

3. To find all files that end with “log” in directory /ora0/admin

$ find /ora0/admin -name “*log” -print

4. To send mails from the server

To mail the contents of message.log to xyz and abc with a subject.

$ mail -s “Messages from Me” “xyz@abc.com” “abc@xyz.com” < message.log

$ uuencode awrrpt_1_2545_2546.txt awrrpt_1_2545_2546.txt |mailx -s “awr” abc@xyz.com

5. To see errors from Alert log file

$ cd alertlogdirectory
$ grep ORA- alertSID.log

6. To see the latest 20 lines in the Alert log file

$ tail -20 alertSID.log

To see the first 20 lines in the Alert log file

$ head -20 alertSID.log

8.To remove ^M character in a file and write the new contents in another tempfile.

$ sed -e ‘s/^M$//’ filename > tempfile

9. Details of the Server

$ uname -a

10. File System Information

$  df -k (in kb)
$  df -h (in gb)

11. Last Reboot Time of the server

$ who -b

12. Memory Size on Server

$ /usr/sbin/prtconf |grep “Memory size”

13. Swap Space on Server

$ /usr/sbin/swap -s

14. Number of CPUs on server

$ /usr/sbin/psrinfo

$ cat /proc/cpuinfo | grep processor (Solaris)

15. Top CPU consuming processes
$ top

$ prstat -J (Used in Solaris)

$ topaz (Used in AIX)

16.To get the users currently logged  in

$ who

To get the details of the user as whom I have logged in

$ who am i

17. To change certain terminal characteristics.

For erasing using <backspace> . In some settings, entering backspace may return garbage values. To avoid this use:

$stty erase ^?

18. Terminal and disk I/O activity and CPU utilization

$ iostat -xtc 5 2

Time: 08:46:51 PM
avg-cpu:  %user   %nice    %sys %iowait   %idle
4.26    0.00    1.45    2.87   91.42

19. To get virtual memory statistics.

$ vmstat 5
procs ———–memory———- —swap– —–io—- –system– —-cpu—-
r  b  swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa
0  0 8 1061668 1094224 7348112    0    0  1625   257    0     0  4  1 91  3

20. To get network-related information.

$ netstat -rn
Kernel IP routing table
Destination     Gateway       Genmask         Flags   MSS Window  irtt Iface
172.168.1.3     0.0.0.0         255.255.255.255 UH         0 0          0 ppp0
172.168.1.3     172.168.1.5  255.255.255.255 UGH       0 0          0 ppp0
172.168.1.2     0.0.0.0         255.255.255.255 UH         0 0          0 ppp1
172.168.1.2     172.168.1.4  255.255.255.255 UGH       0 0          0 ppp1
174.12.3.32     0.0.0.0         255.255.255.240  U          0 0          0 bond0
179.254.0.0     0.0.0.0         255.255.0.           U         0 0          0 bond0
0.0.0.0         164.12.3.46     0.0.0.0               UG        0 0          0 bond0

20. Displays today’s CPU activity so far

$ sar -u 5 5  (Used in Linux)

08:51:50 PM       CPU     %user     %nice   %system   %iowait     %idle
08:51:55 PM       all      0.87      0.00      0.69      0.71     97.73
08:52:00 PM       all      4.66      0.00      1.62      0.93     92.80

Research and Article Contribution : Divya

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