Unix Commands for DBA

Unix Commands
#hostname -?	To find out the options
#hostnaeme -i	IP address
#hostname -f	Full domain Name
#df -k	Free space
#df -h	Human readable space (interns of MB and GB)
#rm -R filename	To remove directory with contents
#netstat -?	Will give ports details (Listening Ports and Establish ports)
#ls -F	To differentiate files and directories( with / means directory , others are files
#cat -n filename	to see the file with numbers
#cp -i sourcefile destinationfile	to avoid over writing the existing file
# mv -i originalfilename  newfilename	to avoid overwriting theexisting file
# rm -r filesname	remove the files in interactive  mode
# ls directory1 directory2	list out files in directory1  and directory 2
# ls -d dierctory	to show only directory name without  its contents
# mkdir  directory1 directory2	we can create many  directory at a time
# mkdir -p /tmp/ch04/test1	The mkdir command checks whether  the directory /tmp exists. If it does not exist, it is created
# cp -r source destination	To copy the directory
# cp -r source1 source2 source3 destination	to copy many  files or dirctories into destination( last is the destination)
#ls -A  directory	to determine the empty directory( if  its not return then empty directory otherwise not empty )
# file filename	to know about file ( whether a  particular file is a binary program, a shell script, or a library)
# chown	to chage the user and droup of the file
# ps -f	to see the full detail( PID and PPID ) of the  process
# kill % job number	to kill the particular job number
# kill PID	To kill the particular process Id
# kill -9 %jobnumber od PID	to kill the process forcebaly
# kill -KILL %jobnumber od PID	to kill the process forcebaly
vi COMMANDS
vi filename	start editing filename, create it if necessary
:wq	write the file to disk and quit(save and quit)
:q!	quit without saving any changes
:w! newfile	write all lines from the entire current file into the file 'newfile', overwriting any existing newfile
:n,m w! newfile	write the lines from n to m, inclusive, into the file newfile, overwriting any existing newfile
Moving the Cursor
h	one space to the left (also try left arrow)
j	one line down (also try down arrow)
k	one line up (also try up arrow)
l	one space to the right (also try right arrow)
$	end of current line
^	beginning of current line
Enter	beginning first word on the next line
G	end of file
:n	line n; use :0 to move the beginning of the file
w	beginning of next word; 5w moves to the beginning of the 5th word to the right
e	end of next word
b	beginning of previous word
Ctrl-b	one page up
Ctrl-f	one page down
%	the matching (, ), [, ], {, or }   (Press % with your cursor on one of these characters to move your cursor its mate.)
Searching for Text
/string	search down for string
?string	search up for string
n	repeat last search from present position
Inserting Text
a	append starting right of cursor
A	append at the end of the current line
i	insert starting left of cursor
I	insert at beginning of the current line
o	open line below cursor, then enter insert mode
O	open line above cursor, then enter insert mode
:r newfile	add the contents of the file newfile starting below the current line
Deleting Text
x	delete single character; 5x deletes 5 characters
dw	delete word; 5dw deletes 5 words
dd	delete line; 5dd deletes ... well you get the idea!
cw	delete word, leaves you in insert mode (i.e. change word)
cc	change line -- delete line and start insert mode
s	change character -- delete character and start insert mode
D	delete from cursor to end of line
C	change from cursor to end of line -- delete and start insert mode
u	undo last change
U	undo all changes to current line
J	join current line with line that follows (press Enter in insert mode to split line)
Navigating Directories and files
pwd	'print working directory' displays the name of the current directory
cd	change directory' command will change the current directory to the directory specified as the argument to the command, as in 'cd /home/WWW-pages/username'. ('cd' without specified parameter will return to your home directory.)
ls	'list files' command displays the files in a directory.
ls -l	long list option' for listing files displays permissions, links, owner,group, file size, modification date, file name.
rm	'remove' command deletes ordinary files in a directory.
mv	move' command moves a file from one location to another. It is also used to rename files, as in 'mv thisfile.txt thatfile.txt'
cp	'copy' command creates a copy of a file.
chmod	change mode' command is used to control access rights to a file or files.
mkdir	make directory' command creates a directory or subdirectory within the current directory.
rmdir	remove directory' command removes a directory or subdirectory. The specified directory must be empty before it can be removed.
find	'find' command is used to locate files.
file	file' command is used to determine the type of information in the file listed as the argument to the command, i.e. text or binary.
cat	cat' command displays the contents of files. It is also used to concatenate files as in "cat file1.txt file2.txt file3.txt > allfiles.txt".
wc	wc' command displays a count of characters, words, and lines in a text file.
sort	'sort' command is used to sort and/or merge text files.
grep	'grep' command searches for text strings in files.

 

Unix for the DBA

How to kill all similar processes with single command (in this case opmn)

ps -ef | grep opmn |grep -v grep | awk ‘{print $2}’ |xargs -i kill -9 {}

Locating Files under a particular directory

find . -print |grep -i test.sql

 Using AWK in UNIX

To remove a specific column of output from a UNIX command – for example to determine the UNIX process Ids for all Oracle processes on server (second column)

ps -ef |grep -i oracle |awk '{ print $2 }'

Changing the standard prompt for Oracle Users

Edit the .profile for the oracle user

PS1="`hostname`*$ORACLE_SID:$PWD>"

 Display top 10 CPU consumers using the ps command

/usr/ucb/ps auxgw | head -11

 Show number of active Oracle dedicated connection users for a particular ORACLE_SID

ps -ef | grep $ORACLE_SID|grep -v grep|grep -v ora_|wc -l

 Display the number of CPU’s in Solaris

psrinfo -v | grep "Status of processor"|wc -l

Display the number of CPU’s in AIX

lsdev -C | grep Process|wc -l

Display RAM Memory size on Solaris

prtconf |grep -i mem

Display RAM memory size on AIX

First determine name of memory device

lsdev -C |grep mem

then assuming the name of the memory device is ‘mem0’

lsattr -El mem0

Swap space allocation and usage

Solaris : swap -s or swap -l

Aix : lsps -a

 Total number of semaphores held by all instances on server

ipcs -as | awk '{sum += $9} END {print sum}'

View allocated RAM memory segments

ipcs -pmb

Manually deallocate shared memeory segments

ipcrm -m '<ID>'

 Show mount points for a disk in AIX

lspv -l hdisk13

 Display amount of occupied space (in KB) for a file or collection of files in a directory or sub-directory

du -ks * | sort -n| tail

Display total file space in a directory

du -ks .

 Cleanup any unwanted trace files more than seven days old

find . *.trc -mtime +7 -exec rm {} \;

 Locate Oracle files that contain certain strings

find . -print | xargs grep rollback

 Locate recently created UNIX files (in the past one day)

find . -mtime -1 -print

 Finding large files on the server (more than 100MB in size)

find . -size +102400 -print

Crontab :

To submit a task every Tuesday (day 2) at 2:45PM

45 14 2 * * /opt/oracle/scripts/tr_listener.sh > /dev/null 2>&1

To submit a task to run every 15 minutes on weekdays (days 1-5)

15,30,45 * 1-5 * * /opt/oracle/scripts/tr_listener.sh > /dev/null 2>&1

To submit a task to run every hour at 15 minutes past the hour on weekends (days 6 and 0)

15 * 0,6 * * opt/oracle/scripts/tr_listener.sh > /dev/null 2>&1