Understanding ioscan

What kind of attached devices?

# ioscan -kfnC disk
will show all disks attached.

# isocan -kfnC tape
will show tape drives attached.

# ioscan -kfnC lan
will show lan cards.

# ioscan -kfnC fc
will show fibre channel interfaces.

# ioscan -kfnC processor
will show the processors in your system

Some of other command

ioscan --- scan the system HW
lssf --- list dev specisl files
insf --- install the device special files
rmsf --- remove the device specisl files
ioinit --- io initialisation.   ¶ 5:54 PM 0 Comments

  To know more wget commands.
http://en.wikipedia.org/wiki/Wget  ¶ 9:08 AM 0 Comments

  To know more abt NIS inUNIX, Check it below link.
http://www.ntlug.org/NIS/Presentation  ¶ 10:43 AM 0 Comments

 

Create user profile and tips

1. Create a user using below command

useradd ram

2.To Set the password fir the

user passwd ram

3.To delete the user

userdel ram

3.To lock the account

usermod -L ram (or) passwd -l ram

4.To release the lock

usermod -U ram

5.To set a expiration date for the user

usermod -e 06/17/2008 ram

Some Tips

To disable an account:
/usr/lbin/modprpw -m alock=YES username

To enable a user account:
/usr/lbin/modprpw -k username

To check status of the account:
/usr/lbin/getprpw -r -m lockout username
It will return a 7 digit number and if the 6th digit is set to 1 that the account is locked

Blocking all the user account

If u want to block all the user for perticular box, Just create one empty file BLOBKALLBUT ROOT
It will be block the all the user and only root can access.

  ¶ 11:47 AM 0 Comments

  Sendamail Tips

Mail spool

Sendmail generally stores its queued mail in the var/spool/mqueue folder. Queued messages are messages that have not reached their final destination yet. There are two files associated with each e-mail message, one beginning with qf, the other beginning df. qf files contain the message header, df files contain the body of the mail message.

Below are the steps to follow to send a mail from unix machine.

Step 1.
Have to enable the mail option in /etc/mail/sendmail.mc file
enable the line called DEAMON_OPTION('port=smtp)
Dont change anything in config file .

Step 2.
Restart the sendmail dameon
service sendmail restart

Step 3.
Use the below command to send mail.
echo " your message "| mail -s " subject" e-mailid

You can use mailx command also to send mail.
echo "your message "| mailx -s "dada" e-mailid

Also stop the mail using this command.
/etc/init.d/sendmail stop | start

check with command mailq whether its sent or not.

To force flush the mailq, run this:

sendmail -v -d8.20 -q

Use mailq to get the mail-id
Then go to /var/spool/mqueue and delete all files with the specified mail-id on the end:
rm *

Labels: Sendamail Tips

  ¶ 3:59 AM 0 Comments

  How to install and configure Telnet services.
To install the telnet service, login to the server as the root user account

1)
Fedora linux user following command:-
yum install telnet-server telnet

2)
chkconfig telnet on
service xinetd reload

3)
Go to the /etc/securitty file.

If tty has 1-11 listed lin by line, Add the pts 1 to 11 in end of the line as the same format of tty.
save the file and now you can able to telnet from the windows or Linux machine.

4)
telnet ipaddress.  ¶ 3:34 AM 0 Comments

  How to Configure Samba on Fedora Linux

Samba can be used to allow connectivity between Linux and Windows(95,98,NT,2000)
Samba deamon is smbd. All of samba is configured in one single file, the smb.conf file.
This file, located at /etc/samba/smb.conf, allows you to specify which resources on the linux machine you wish to share and who they can be accessed by.

Below steps are followed to configure samba in Fedora Linux.
Step 1:
First create a directories and users
Create directories for Samba to use with Windows

#mkdir ram
Now we need to create users to access this directiory

#useradd ram
Now create a password for this user using the following command

#smbpasswd -a ram

Step 2:
Samba configuration
By default samba configuration file located at /etc/samba/smb.conf
In this file main section is Global where you can define all parameters and the example as follows

[global]
workgroup = MYGROUP
server string = Samba Server
log file = /var/log/samba/%m.log
max log size = 50
dns proxy = No
cups options = raw

[homes]
comment = Home Directories
read only = No
browseable = No

[printers]
comment = All Printers
path = /usr/spool/samba
printable = Yes
browseable = No

[samba]
comment = ram
path = /freesapce/Ramkumar
valid users = ram
writable = yes

Add at in inside samba part.
* which path you need to share the folder in Linux.
* which user have a authorised to login.

Step 3:
Samba Service

Now that everything has been configured, the final step is to start the samba service. Samba runs in the background
as a linux daemon. Therefore, it can be controlled by typing:

service smb start
service smb stop
service smb restart
(or)
#/etc/init.d/samba restart

Note that once the computer is restarted or shutdown, the samba service won't start up again.

Step 4:
Connect to the samba server

Type the ip address in run prompt.
it will connect to linux box.
and try to access as your username and passwd.
then it connect and show the folder which you have created.
Now you can share the file with unix machine.  ¶ 3:04 AM 0 Comments

  How to Install Fedora

1.If you have already installed fedora mean , You need to uninstal that.
2.Using windows OS, u can remove the file which had occipied by fedora os.
3.for that,
select mycomputer ->left click ->select manage -> select disk management ->
Remove linux file system spaces.
4.Insert the fedora 6.0 cd.
For that u need to reboot and press f8 + select DVD ROM
It will take time for loading ata-piix driver
5.select options.
6.Select custom layout option.
Inside u have to partition for below path
/root -1000MB
/boot -1000MB
/home -1000MB
/swap -1000MB
/usr -5000MB
/opt -1000MB
7.select DHCP option
8.Give the root password
9.Select sofware which u want.
make sure that all tha packages are selected for perticular software.
10.select the webserver and samba also
11.then It will take one hour to install all the software and packages using command rpm --verify mysql
13.After get over.reboot the system.

The fedora login page should come if the insatallation has completed successfully.

Note: If not come check all the software installed or not.
check the packages allso.

Partitioning and Formatting Second Hard Drive - (ext3)

Partioining have to do after the system reboot.
This is for collect the free space and configure.

First, you will need to run the fdisk command in order to partition the disk. For this example, I only want to create one ext3 partition. Here is an example session:

1)For HP system ---> lv
For sun OS ---> NEWFS

For fedora issue the command
fdisk /dev/hda

2)select p to print the partitioned space
it will be listed in cylinder wise

dev/hda1 1 255
dev/hda2 .. ...
dev/hda7 4718 5099

3)if i want to partition for free space into hda8
select the command n
give the first cylinder . to 51000
+MB to 34000MB (remaining space)
save and exit

4)Issue command partprobe(reboot the system after partition)

creating ext3 File system
mkfs ("make a filesystem") is the standard Unix command for formatting a disk partition with a specific filesystem. The basic syntax is:

mkfs.ext3 /dev/hdsa8


The ext3 or third extended filesystem is a journalled file system that is commonly used by the GNU/Linux operating system. It is the default file system for many popular Linux distributions.


Mounting the file system
Now that the new hard drive is partition and formated, the last step is to mount the new drive. For this example, I will be mounting the new hard drive on the directory /hda8.

if u want u can make one directory freespace

mkdir fressspace

mount /fev/hda /fressapace/

if u do unmount /fressspace/ then the space will add into none folder.

at the end of the section u have to add the fresspace to /etc/fstab/
add the fressapce at end and like

/dev/hda8/ /fressapce/ ext3 defaults 1 2

save and reboot the system reboot -f

How to change the HOST name

step 1.

vi /etc/host
Add at end of line
IP Address domainname.domain.com domainname

step 2.
vi /et/sysconfig/network
Add at end of line
HOSTNAME=domainname.domain.com

step 3.
vi /etc/sysconfig/network-scripts/ifcfg-eth0
Add at the end of line
HOSTNAME=domainname  ¶ 1:51 AM 0 Comments

  SFTP configuration
Its same procedure as we discussed in ssh.

1.Generate the key first
$ ssh-keygen -trsa
it will be create and stored in .ssh directory

2.copy the key to destination host.
$ ls -a
. .. authorized_keys id_rsa id_rsa.pub known_hosts
Here u need to copy the id_rsa.pub to destination host.

$ scp id_rsa.pub ram@172.1.00.00:~/.ssh/authorized_keys
ram@172.1.00.00's password:
id_rsa.pub 100% |*****************************| 233 00:00

3.do sftp to which host u need to do
$ sftp 172.1.00.00
Connecting to 172.1.00.00...
sftp>
You can do ftp with scure way now.  ¶ 9:48 PM 0 Comments

  SSH configuration for one host to other host in UNIX.

1.Generate the key from which host to need to do for ssh
$ ssh-keygen -trsa
it will be create and stoerd in .ssh directory

2.copy the key to distination host.
$ ls -a
. .. authorized_keys id_rsa id_rsa.pub known_hosts
Here u need to copy the id_rsa.pub to destination host.

$ scp id_rsa.pub ram@111.11.1.1:~/.ssh/authorized_keys
ram@111.11.1.1's password:
id_rsa.pub 100% |*****************************| 233 00:00

3.Once successfully copied, do the ssh it wont ask any password
[ram@bc .ssh]$ ssh 111.11.1.1
Wel Come To Dax Server
[ram@dax ~]$

Note: Before do this configuration make sure that the username for both host are same.  ¶ 9:32 PM 0 Comments

  How to start ftp service.
Linux is configured to run the Telnet and FTP server, but by default, these services are not enabled.

Configure FTP and starting the deamons.
Edit the files /etc/vsftpd.ftpusers and /etc/vsftpd.user_list and remove the 'root' line from each file.

[root@rak tmp]# /etc/init.d/vsftpd start
[root@rak tmp]# /etc/init.d/vsftpd stop
(or)
[root@rak tmp]# /etc/init.d/vsftpd restart

[root@rak ~]# pgrep httpd (it will be tell the port number which is enabled for ftp)  ¶ 3:22 AM 0 Comments