Mar
22

Adding permanent and temporary routes to SUN Solaris

Adnan Khurshid on March 22nd, 2011

Normally, if you use the man command to find out the method to add routes to the SUN machine, it will come up with the ‘route add’ command but is that command enough to add the routes securely to the system? Well, let us find it out. Before getting involved, just for the sake of […]

Continue reading about Adding permanent and temporary routes to SUN Solaris

Operating Systems No comments »
Mar
4

Basics of Oracle System Processes

Adnan Khurshid on March 4th, 2011

Let’s discuss the processes running in Oracle database and their functions. DBW`: Database Writer, this process writes the data from buffer cache to the DB file and this operation of reading and writing is done in blocks. The default block size in Oracle is 8192 bytes, however it can be modified as required. Starting from […]

Continue reading about Basics of Oracle System Processes

Databases 1 Comment »
Feb
22

How to find large files and directories in Unix/Linux

Adnan Khurshid on February 22nd, 2011

Finding large files: Suppose we are facing a disk space issue in one system user directory and we want to find out which files are using most of the disk space, we can run the following command to find it out: <36 SMSC :/export/home2/mml/tmp> find /export/home2/mml/ -size +400000| sort –r| head –3 /export/home2/mml/sms/bin/core_20110119152929_14771 /export/home2/mml/sms/bin/core_20101231115847_13489 /export/home2/mml/sms/bin/core_20101204105309_5074 […]

Continue reading about How to find large files and directories in Unix/Linux

Operating Systems No comments »
Feb
18

How to determine which processes are taking most of your CPU and Memory in Linux

Adnan Khurshid on February 18th, 2011

Well, we know that command ‘ps –aux’ will show all the processes currently running on the system. We can sort the output of this command by using sort command piped after ps. We discussed about sort command before, you might want to have a look at it here. Lets first check the output of ps […]

Continue reading about How to determine which processes are taking most of your CPU and Memory in Linux

Operating Systems No comments »
Feb
17

How to get columns from editor segregated by a delimiter in Linux

Adnan Khurshid on February 17th, 2011

This will be more understandable if we take it by an example. Let’s see how many users we have on the system: linux:~ # cat /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/bin/bash daemon:x:2:2:Daemon:/sbin:/bin/bash lp:x:4:7:Printing daemon:/var/spool/lpd:/bin/bash mail:x:8:12:Mailer daemon:/var/spool/clientmqueue:/bin/false news:x:9:13:News system:/etc/news:/bin/bash uucp:x:10:14:Unix-to-Unix CoPy system:/etc/uucp:/bin/bash games:x:12:100:Games account:/var/games:/bin/bash man:x:13:62:Manual pages viewer:/var/cache/man:/bin/bash at:x:25:25:Batch jobs daemon:/var/spool/atjobs:/bin/bash wwwrun:x:30:8:WWW daemon apache:/var/lib/wwwrun:/bin/false ftp:x:40:49:FTP account:/srv/ftp:/bin/bash postfix:x:51:51:Postfix Daemon:/var/spool/postfix:/bin/false sshd:x:71:65:SSH daemon:/var/lib/sshd:/bin/false […]

Continue reading about How to get columns from editor segregated by a delimiter in Linux

Operating Systems 12 Comments »
Feb
15

Short Message Center – Message Flows

Adnan Khurshid on February 15th, 2011

The function of short message center is to receive, store and schedule messages for delivery. There are mainly three network flows involved in the message receiving and delivery. They are as follows: 1) Mobile Origination 2) Mobile Termination 3) Alert Message Flow Lets analyze the flows one by one. 1) Mobile Origination Most of the […]

Continue reading about Short Message Center – Message Flows

Value Added Services 3 Comments »
Feb
11

How to login to ISQL*PLUS as sysdba in Oracle

Adnan Khurshid on February 11th, 2011

There are mainly 4 steps involved. 1) Create users for ISQL*PLUS DBA URL 2) Grant webdba role to those users 3) Restart the httpserver 4) Access the webpage @ http://localhost:port/isqlplus/dba Let’s follow these steps. 1) To create users, first you’ll have to define java_home and oracle_home and then run this weird long command to get […]

Continue reading about How to login to ISQL*PLUS as sysdba in Oracle

Databases No comments »
Feb
11

How to change the port number for iSQL*PLUS in Oracle

Adnan Khurshid on February 11th, 2011

The default port to access iSQL*PLUS is 5560. You can access iSQL*PLUS with the following URL given that the oracle is installed on the local host ‘http://localhost:5560/isqlplus/’ To change the port number, modify the file “http-web-site.xml” as given below:

Continue reading about How to change the port number for iSQL*PLUS in Oracle

Databases No comments »
Feb
10

How to retrieve command history in Linux/Unix servers

Adnan Khurshid on February 10th, 2011

The command history is stored in the file ‘bash_history’ which you can access as follows: linux:~ # less ~/.bash_history The file contains a list of all the commands which are stored in the buffer. You can also see these commands in sequence with the line numbers by using ‘history’ command. linux:~ # history The history […]

Continue reading about How to retrieve command history in Linux/Unix servers

Operating Systems 1 Comment »