This document provides a summary of common UNIX commands for database administrators (DBAs). It begins with an introduction and is organized into sections on file and directory navigation, file permissions, OS user management, process monitoring, and performance monitoring. Specific commands covered include ls, cd, cp, find, head, tail, less, more, cat, mkdir, rm, rmdir, touch, whereis, which, umask, chmod, chown, chgrp, useradd, usermod, userdel, passwd, who, groupadd, groupdel, ps, uname, hostname, gzip, gunzip, vmstat, top, mpstat, sar, and df.

1. Most Frequently Used UNIX Commands For DBAs
WHITE PAPER
Author: Suparna Chaudhuri
Table of Contents
Table of Contents.............................................................................................................................................1
Introduction......................................................................................................................3
File & Directory Navigation.............................................................................................4
..........................................................................................................................................4
File Permissions...............................................................................................................7
OS Users Management.....................................................................................................8

2. Most Frequently Used UNIX Commands For DBAs
Process Monitoring...........................................................................................................9
uname and hostname......................................................................................................10
Compress Files...............................................................................................................10
Performance Monitoring................................................................................................11
CPU Utilization..............................................................................................................11
Disk Space Usage...........................................................................................................13
CRON.............................................................................................................................14
References......................................................................................................................15
About the Authors..........................................................................................................15

3. Most Frequently Used UNIX Commands For DBAs
Introduction
This paper contains common UNIX commands for DBAs. This is not a complete but a compact
list of commands used on regular basis. This will give you a jumpstart on some of the common
Linux commands. All UNIX commands and filenames are case sensitive.

4. Most Frequently Used UNIX Commands For DBAs
File & Directory Navigation
cat
cat filename
Display a filename
cat /etc/passwd
cat bigfile | more
cd
cd dirname
Change from one directory to other directory.
cd /oraData
cp
cp file1 file2
Copies one file/directory to specified location.
cp data.txt /tmp
file
file filename
Identifies the type of file type like binary, text.
File /dev/wd0a
file compressed.gz
find
find filename/dir
Finds a file/directory.
find /usr –name *stat
Find every file under the directory /usr ending in "stat".
head
head filename
Shows the beginning of a file.
head –n 5 mydoc.txt

5. Most Frequently Used UNIX Commands For DBAs
To view the first n number of lines.
less
less filename
Allows you to quickly view the file.
less table1
It will display the top of the file, ‘table1’.
ls
ls dirname
List directory contents
ls /home/usr/doc/book
mkdir
mkdir dirname
Creates the specified directory.
mkdir mydir
more
more filename
The more command writes your file onto the screen one page at a time.
ls –a | more
mv
mv file1 file2
Moves the location of or renames a file/directory.
mv my_file.txt your_file.txt
pwd
Shows the current directory the user is in
root>pwd
/u01/app/oracleproduct/9.2.0.1.0
rm
rm filename
Removes a file.

6. Most Frequently Used UNIX Commands For DBAs
rm my_file.txt
rm –R /archievelog
rmdir
rmdir dirname
Removes a directory.
rmdir backup
tail
tail filename
Shows the end of a file.
tail dblog.txt
This command will print the last ten line of the file named dblog.txt.
tail dblog.txt –n 100
This command will print the last 100 lines of the file named dblog.txt.
touch
touch filename
Creates a blank file or modifies an existing file”s access and modification time.
touch newfile.log
Creates a file known as newfile.log, if it does not already exist. If the file already exists the
accessed and modification time will be updated for the file, newfile.log.
whereis
whereis filename
Shows the location of a file.
whereis –b ls
ls: /bin/ls
which
which filename
Shows the location of a file if it is in your PATH.
oracle> which sqlplus
The "which" command searches PATH setting for occurrences of the specified executable.

7. Most Frequently Used UNIX Commands For DBAs
File Permissions
umask
When user creates a file or directory under Linux or UNIX, he/she creates it with a default set of
permissions. The user file-creation mode mask (umask) is used to determine the file permission
for newly created files. It can be used to control the default file permission for new files. It is a
four-digit octal number.
You can setup umask in /etc/bashrc or /etc/profile file for all users.
The octal notations are as follows:
Octal value : Permission
0 : read, write and execute
1 : read and write
2 : read and execute
3 : read only
4 : write and execute
5 : write only
6 : execute only
7 : no permissions
root>umask 022
chmod
Changes the permission of a file.
Permissions
u - User who owns the file.
g - Group that owns the file.
o - Other.
a - All.
r - Read the file.
w - Write or edit the file.
x - Execute or run the file as a program.
root > chmod 644 file.htm
root> chmod o+rwx *.log
root> chmod g+r *.log
chown
chown command changes the user and/or group ownership for a given file.
chown owner-user file
chown owner-user:owner-group file
root> ls –l testjar.sh

8. Most Frequently Used UNIX Commands For DBAs
-rw-r--r-- 1 root root 0 Aug 31 05:48 testjar.sh
root> chown schau testjar.sh
root> ls –l testjar.sh
-rw-r--r-- 1 schau root 0 Aug 31 05:48 testjar.sh
chgrp
chgrp command changes group associated to a file/folder from one group to other.
Change group name:sales of a file to other group name:hrgroup
chgrp hrgroup file1
OS Users Management
useradd
This command is used to create new users and also update default new user information.
root> useradd -G oinstall -g dba -d /usr/users/my_user -m -s /bin/ksh my_user
The "-G" flag specifies the primary group.
The "-g" flag specifies the secondary group.
The "-d" flag specifies the default directory.
The "-m" flag creates the default directory.
The "-s" flag specifies the default shell.
When a user account is created, some extra information is associated with account by default. To
view these default values, use the -D option along with this command.
[root@houora27 ~]# useradd -D
GROUP=100
HOME=/home
INACTIVE=-1
EXPIRE=
SHELL=/bin/bash
SKEL=/etc/skel
usermod
The "usermod" command is used to modify the user settings after a user has been created:
root> usermod -s /bin/csh my_user
userdel
The "userdel" command is used to delete existing users:
root> userdel -r my_user

9. Most Frequently Used UNIX Commands For DBAs
The "-r" flag removes the default directory.
passwd
The "passwd" command is used to set, or reset, the users login password:
root> passwd my_user
who
The "who" command can be used to list all users who have OS connections:
root>who
root>who | head -5
root>who | tail -5
root>who | grep –I ora
root>who | wc -1
The "head -5" command restricts the output to the first 5 lines of the who command.
The "tail -5" command restricts the output to the last 5 lines of the who command.
The "grep -i ora" command restricts the output to lines containing "ora".
The "wc -l" command returns the number of lines from "who", and hence the number of
connected users.
groupadd
groupadd command is used to create group accounts. It updates the /etc/group file accordingly.
root> ls –l testjar.sh
If you want to create a group with a specific group id use below command.
root> groupadd dbgrp –g 9090
groupdel
This command will remove a group.
groupdel dbgrp
Process Monitoring
ps
This command lists current process information.
[oracle@houora27 oracleData]$ ps
PID TTY TIME CMD

10. Most Frequently Used UNIX Commands For DBAs
12326 pts/1 00:00:00 bash
12874 pts/1 00:00:00 ps
[oracle@houora27 oracleData]$ ps -ef|grep -i ora
oracle 11217 1 0 Jul22 ? 00:01:23
/opt/Oracle/DB10gR2/beta4/product/10.2.0/db_1/bin/tnslsnr LISTENER -inherit
oracle 11226 1 0 Jul22 ? 00:03:52 ora_pmon_BETA4
oracle 11228 1 0 Jul22 ? 00:00:06 ora_psp0_BETA4
oracle 11230 1 0 Jul22 ? 00:02:07 ora_mman_BETA4
oracle 11232 1 0 Jul22 ? 00:05:34 ora_dbw0_BETA4
oracle 11234 1 0 Jul22 ? 02:13:47 ora_lgwr_BETA4
oracle 11236 1 0 Jul22 ? 00:03:43 ora_ckpt_BETA4
oracle 11238 1 0 Jul22 ? 00:04:32 ora_smon_BETA4
oracle 11240 1 0 Jul22 ? 00:00:00 ora_reco_BETA4
-e – to display all processes
-f – to display full format listing
uname and hostname
The "uname" and "hostname" commands can be used to get information about the host:
[oracle@houora27 oracleData]$ uname –a
Linux houora27 2.6.9-34.ELsmp #1 SMP Fri Feb 24 16:54:53 EST 2006 i686 i686 i386
GNU/Linux
[oracle@houora27 oracleData]$ hostname
houora27
Compress Files
To save space on the filesystem user can compress files such as archived redo logs. This can be
using gzip. The gzip command results in a compressed copy of the original file with a ".gz"
extension. The gunzip command reverses this process:
gzip
gzip myfile
Compresses the file myfile, making it myfile.gz. Note. When doing this the original file will no
longer exist on the drive.
gunzip
gunzip -f myfile.gz

11. Most Frequently Used UNIX Commands For DBAs
Uncompress the file myfile.gz and if the uncompressed file(s) already exist force an overwrite.
When doing this the file myfile.gz will no longer be on the drive.
gunzip -c myfile.gz > myfile.txt
Uncompress the file myfile.tz to the myfile.txt file, however, don't delete the .gz file. This is
useful if you don't want to delete the .gz and keep it with the uncompressed file.
Performance Monitoring
vmstat
vmstat will display the memory usage.
[oracle@houora27 oracleData]$ vmstat 5 3
Displays system statistics (5 seconds apart; 3 times)
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
1 0 21744 40832 78420 3535796 0 0 1 4 2 5 19 41 35 5
1 0 21744 40768 78440 3535776 0 0 0 188 1041 114 25 27 44 4
1 0 21744 40784 78460 3535756 0 0 0 160 1036 108 24 28 45 4
vmstat output contains the following fields:
Procs – r: Total number of processes waiting to run
Procs – b: Total number of busy processes
Memory – swpd: Used virtual memory
Memory – free: Free virtual memory
Memory – buff: Memory used as buffers
Memory – cache: Memory used as cache.
Swap – si: Memory swapped from disk (for every second)
Swap – so: Memory swapped to disk (for every second)
IO – bi: Blocks in. i.e blocks received from device (for every second)
IO – bo: Blocks out. i.e blocks sent to the device (for every second)
System – in: Interrupts per second
System – cs: Context switches
CPU – us, sy, id, wa, st: CPU user time, system time, idle time, wait time
CPU Utilization
top
The top program provides a dynamic real-time view of a running system. It displays system
summary information; list of tasks currently being managed by the Linux kernel.
The top command monitors CPU utilization, process statistics, and memory utilization.

12. Most Frequently Used UNIX Commands For DBAs
root>top
top - 12:04:31 up 43 days, 18:31, 1 user, load average: 1.01, 1.20, 1.24
Tasks: 114 total, 2 running, 112 sleeping, 0 stopped, 0 zombie
Cpu(s): 24.8% us, 27.2% sy, 0.0% ni, 45.0% id, 3.0% wa, 0.0% hi, 0.0% si
Mem: 4148916k total, 4123052k used, 25864k free, 4136k buffers
Swap: 6289436k total, 21672k used, 6267764k free, 3631960k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2470 root 25 0 11464 4552 2584 R 99.9 0.1 3354:21 snmpd
11295 oracle 16 0 2340m 2.1g 2.1g S 0.7 53.1 1188:31 oracle
11299 oracle 16 0 2340m 2.1g 2.1g S 0.7 53.0 549:18.14 oracle
11301 oracle 16 0 2344m 2.1g 2.1g S 0.7 52.6 180:57.14 oracle
11303 oracle 16 0 2338m 2.1g 2.1g S 0.7 52.3 58:32.22 oracle
16366 root 17 0 3336 944 740 R 0.7 0.0 0:00.05 top
mpstat
For multiple CPU system mpstat command displays the utilization of each CPU individually. It
reports processors related statistics.
root>mpstat
Linux 2.6.9-34.ELsmp (houora27) 09/03/2013
12:07:09 PM CPU %user %nice %system %iowait %irq %soft %idle intr/s
12:07:09 PM all 18.13 0.93 40.86 4.62 0.01 0.00 35.44 1065.19
sar
This command displays today’s cpu activity.
root>sar
Linux 2.6.9-34.ELsmp (houora27) 09/03/2013
12:00:01 AM CPU %user %nice %system %iowait %idle
12:10:01 AM all 24.42 0.00 28.04 4.67 42.87
12:20:01 AM all 24.60 0.00 28.10 4.57 42.73
12:30:01 AM all 24.36 0.00 28.12 4.69 42.84
12:40:01 AM all 24.89 0.00 28.18 3.09 43.85
12:50:02 AM all 24.42 0.00 28.03 2.95 44.60
01:00:01 AM all 24.51 0.00 28.09 3.18 44.22
01:10:01 AM all 24.33 0.00 28.10 3.11 44.46
01:20:01 AM all 24.43 0.00 28.05 2.97 44.55
Where,
%user: Percentage of CPU utilization that occurred while executing at the user level
(application).

13. Most Frequently Used UNIX Commands For DBAs
%nice: Percentage of CPU utilization that occurred while executing at the user level with nice
priority.
%system: Percentage of CPU utilization that occurred while executing at the system level
(kernel).
%iowait: Percentage of time that the CPU or CPUs were idle during which the system had an
outstanding disk I/O request.
%idle: Percentage of time that the CPU or CPUs were idle and the system did not have an
outstanding disk I/O request.
Disk Space Usage
df
This command displays the file system disk space usage.
root>df –k
displays output in bytes
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 20641788 9019860 10573288 47% /
/dev/sdb1 70557052 14689764 52283192 22% /Misc
/dev/sda1 101086 11506 84361 13% /boot
none 2063504 35880 1922804 2% /dev/shm
/dev/sda6 2063504 35880 1922804 2% /dev/shm
/dev/sda5 20641788 5846244 13746904 30% /opt
/dev/sdc1 288362876 171807444 101907368 63% /oracleBackup
/dev/sdd1 288362876 260358600 13356212 96% /oracleData
root>df –h
displays output in human readable form.
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 8.7G 11G 47% /
/dev/sdb1 68G 15G 50G 22% /Misc
/dev/sda1 99M 12M 83M 13% /boot
none 2.0G 36M 1.9G 2% /dev/shm
/dev/sda6 2.0G 36M 1.9G 2% /dev/shm
/dev/sda5 20G 5.6G 14G 30% /opt
/dev/sdc1 276G 164G 98G 63% /oracleBackup
/dev/sdd1 276G 249G 13G 96% /oracleData
root>df –T
displays what type of file system
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/sda2 ext3 20641788 9019860 10573288 47% /

14. Most Frequently Used UNIX Commands For DBAs
/dev/sdb1 ext3 70557052 14689764 52283192 22% /Misc
/dev/sda1 ext3 101086 11506 84361 13% /boot
none tmpfs 2063504 35880 1922804 2% /dev/shm
/dev/sda6 ext3 2063504 35880 1922804 2% /dev/shm
/dev/sda5 ext3 20641788 5846244 13746904 30% /opt
/dev/sdc1 ext3 288362876 171807444 101907368 63% /oracleBackup
/dev/sdd1 ext3 288362876 260358600 13356212 96% /oracleData
CRON
Crontab command is used to schedule commands to be executed periodically.
Using below command you can see what crontabs are currently running on your system.
root> crontab -1
There are two methods of editing the crontab file.
You can use the "crontab -l > filename" option to list the contents and pipe this to a file. After
editing the file you can apply it using the "crontab filename":
Login as root
crontab -l > newcrontabfile
Edit newcrontabfile file.
crontab newcrontabfile
You can use the "crontab -e" option to edit the crontab file directly.
root> crontab –e
* * * * * /bin/execute/test.sh
There are 5 stars which represent different date parts in the following order:
minute (from 0 to 59)
hour (from 0 to 23)
day of month (from 1 to 31)
month (from 1 to 12)
day of week (from 0 to 6) (0=Sunday)
Using below statement you can schedule the script to run at 1AM every Friday.
0 1 * * 5 /bin/execute/test.sh

15. Most Frequently Used UNIX Commands For DBAs
References
1. http://www.tjhsst.edu/~dhyatt/superap/unixcmd.html
2. http://kb.iu.edu/data/afsk.html
About the Authors
Name Suparna Chaudhuri
E-Mail suparna.chaudhuri@wipro.com
Expertise Oracle
Employee ID 142476

16. Most Frequently Used UNIX Commands For DBAs
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