Tuesday, May 3, 2011

Convert Dynamic Disk to basic Disk in DOS

Using DiskPart.exe in command line

1. Open Command Prompt as Administrator Privileges.

2. Type the command:

DiskPart.exe

3. At the DISKPART prompt, type:

select diskN

to select the dynamic disk that you want to convert.

4. At the DISKPART prompt, type:

clean

to delete all volumes on the disk.

5. Then, at the DISKPART prompt, type:

convert basic

to begin revert the disk to basic drive.

3. In the command prompt, type diskpart and press enter. (See screenshot above)

4. Type list disk and press enter.
NOTE: Make note of the disk number (ex: Disk 1) that you want to convert to a basic disk.

5. Type select disk # and press enter.
NOTE: Substitute # with the actual disk number that you want to convert to a dynamic disk. For example, select disk 1.

6. Type detail disk and press enter.
NOTE: This will give you a list of all the volume numbers on the selected disk number that you will need to delete in steps 7 and 8 below.

A) If you do not have any volumes listed, then you can go to step 10.

7. Type select volume # and press enter.
NOTE: Substitute # with a volume number listed in step 6. For example, select volume 3.

8. Type delete volume and press enter.

9. Repeat steps 7 an 8 for each volume # listed in step 6 until you have deleted all volume #'s.

10. When done, type select disk # and press enter.
NOTE: You would use the same one from step 5 above. For example, select disk 1.

11. Type convert basic and press enter.

12. When done, type exit and press enter.

13. Close the command prompt.

14. You can now create partitions on the now basic disk if you like.
NOTE: Restart the computer if you did step 2 instead.

Network Cables

The two most common unshielded twisted-pair (UTP) network standards are the10 Mhz 10BASE-T Ethernet and the 100Mhz 100BASE-TX Fast Ethernet. The 100BASE-TX standard is quickly becoming the predominant LAN standard. If you are starting from scratch, to build a small home or office network, this is clearly the standard you should choose. This article will show you how to make cables which will work with both standards.

ABOUT LAN :- A LAN can be as simple as two computers, each having a network interface card (NIC) or network adapter and running network software, connected together with a crossover cable.
The next step up would be a network consisting of three or more computers and a hub. Each of the computers is plugged into the hub with a straight-thru cable (the crossover function is performed by the hub).
About cables and connector :- CAT 5 cable has four twisted pairs of wire for a total of eight individually insulated wires. Each pair is color coded with one wire having a solid color (blue, orange, green, or brown) twisted around a second wire with a white background and a stripe of the same color. The solid colors may have a white stripe in some cables. Cable colors are commonly described using the background color followed by the color of the stripe; e.g., white-orange is a cable with a white background and an orange stripe.
The straight through and cross-over patch cables discussed in this article are terminated with CAT 5 RJ-45 modular plugs. RJ-45 plugs are similar to those you'll see on the end of your telephone cable except they have eight versus four or six contacts on the end of the plug and they are about twice as big. Make sure they are rated for CAT 5 wiring. (RJ means "Registered Jack"). Also, there are RJ-45 plugs designed for both solid core wire and stranded wire. Others are designed specifically for one kind of wire or the other. Be sure you buy plugs appropriate for the wire you are going to use. I use plugs designed to accommodate both kinds of wire.

Modular Plug Crimp Tool. You will need a modular crimp tool. This one is very similar to the one I have been using for many years for all kinds of telephone cable work and it works just fine for Ethernet cables. You don't need a lot of bells and whistles, just a tool which will securely crimp RJ-45 connectors. Even though the crimper has cutters which can be used to cut the cable and individual wires, and possibly stripping the outer jacket, I find that the following tools are better for stripping and cutting the cable.
COLOR-CODE STANDARDS :-Let's start with simple pin-out diagrams of the two types of UTP Ethernet cables and watch how committees can make a can of worms out of them. Here are the diagrams:
Note that the TX (transmitter) pins are connected to corresponding RX (receiver) pins, plus to plus and minus to minus. And that you must use a crossover cable to connect units with identical interfaces. If you use a straight-through cable, one of the two units must, in effect, perform the cross-over function.
Note that pins 4, 5, 7, and 8 and the blue and brown pairs are not used in either standard. Quite contrary to what you may read elsewhere, these pins and wires are not used or required to implement 100BASE-TX duplexing--they are just plain wasted.
Now, all you need to remember, to properly configure the cables, are the diagrams for the two cable ends and the following rules:
  • A straight-thru cable has identical ends
  • A crossover cable has different ends.
LET'S MAKE SOME CABLES:-
1. Pull the cable off the reel to the desired length and cut.
2. Spread and arrange the pairs roughly in the order of the desired cable end.
3. Untwist the pairs and arrange the wires in the order of the desired cable end. Flatten the end between your thumb and forefinger. Trim the ends of the wires so they are even with one another. It is very important that the unstripped (untwisted) end be slightly less than 1/2" long. If it is longer than 1/2" it will be out-of-spec and susceptible to crosstalk. If it less than slightly less than 1/2" it will not be properly clinched when RJ-45 plug is crimped on.. Flatten again. There should be little or no space between the wires.
Hold the wire near the RJ-45 plug with the clip down and firmly push it into the left side of the front of the crimper (it will only go in one way). Hold the wire in place squeeze the crimper handles quite firmly. This is what will happen:
(Crimp it once.) The crimper pushes two plungers down on the RJ-45 plug. One forces what amounts to a cleverly designed plastic plug/wedge onto the cable jacket and very firmly clinches it. The other seats the "pins," each with two teeth at its end, through the insulation and into the conductors of their respective wires.
Test the crimp...
If done properly an average person will not be able to pull the plug off the cable with his or her bare hands. And that quite simply, besides lower cost, is the primary advantage of twisted-pair cables over the older thinwire, coaxial cables. In fact, I would say the RJ-45 and ease of its installation is the main reason coaxial cable is no longer widely used for small Ethernets. But, don't pull that hard on the plug. It could stretch the cable and change its characteristics. Look at the side of the plug and see if it looks like the diagram and give it a fairly firm tug to make sure it is crimped well.


Read more: http://networkupd8.blogspot.com/2009/12/network-cables.html#ixzz1LHXNlLdg

NFS SERVER

NFS
NFS -> NFS stand for Network File Sharing
Using NFS you can share file on Network.NFS server allow us to share file on client side and vice-versa.
Using NFS server we can easily access any file and directory on client side.

Note -> Disabled Firewall

Note -> For NFS rpm you must need a rhel 5 DVD OR Yum configure
On your system OR an active internet connection to download
NFS rpm.
If Yum is configure on your system then login as a
Root and type,
< Yum -y install nfs* >
If you have a rhel 5 DVD then mount the DVD on any
Directory. For e.g., I mount a DVD on /mnt directory. Now login
As a root and type,
< rpm -ivh /mnt/Server/nfs* >

Now NFS package is installed on your system.

NFS works on Port number 2049/tcp -- To check Port number file is "/etc/services"
---------------------------------------------------------------------------
Server Side Configuration
On Server Side the configuration file is
< /etc/exports >
Open the /etc/exports file in any Linux editor. I suggest you open it in
VIM.
VI /etc/exports
File is blank. Now write in the file you want to share on the network for
End-Users.
For eg. I am sharing a /var/ftp/pub directory and /home directory. Enter the
these lines in /etc/exports file.

/var/ftp/pub *(ro,sync)
/home 10.10.1.20(ro,sync)

Now save & exit from file.
------------------------------------------------------------------------------------------
Here, in the /etc/exports file we write the share directory /var/ftp/pub
And in the front of we write {*(ro, sync} this mean that,

Asterisk (*) mean that you can share the /var/ftp/pub directory on all the
PC connected in the same network.

(ro) means that you have read only permission on /var/ftp/pub. You can change
{ro} to {rw).{rw} mean that you have read and write permission on
/var/ftp/pub/ directory.

(sync) stand for synchronization mean that accuracy in time to matching data.
If you want share a directory on a particular IP address then write the IP
of particular machine corresponding to the share directory.For eg
/home 10.10.1.20(ro,sync)
-----------------------------------------------------------------------------------------
After, configure the /etc/exports file restart the NFS services
service portmap restart
service nfs restart
PORTMAP -> The portmap service can be used with TCP wrappers' hosts access files (/etc/hosts.allow and /etc/hosts.deny) to control which remote systems are permitted to use RPC-based services on the server.
If you want to permanent restart NFS services during next reboot Use
Chkconfig portmap on
Chkconfig nfs on
--------------------------------------------------------------------------------------------
Now, if you want to know what you are sharing on server side, you can see it in two ways.
1. Open the /etc/exports file
2. Showmount -e 10.10.10.254 here 10.10.10.254 is server ip address.
--------------------------------------------------------------------------------------------
On Clint Side
On client side if you want to know that what is sharing from server side
login as root and type
showmount -e 10.10.10.254 server ip address result is look like this
/var/ftp/pub *(ro,sync)
/home 10.10.10.20(ro,sync)

If server gives you write permission on any share directory the mount the directory and you can
edit it. For eg
mount -t nfs 10.10.10.254:/var/ftp/pub /mnt
ls /mnt

Read more: http://networkupd8.blogspot.com/2010/12/nfs-server-in-linux.html#ixzz1LHUdga00

SAMBA SERVER


Samba Server -> It is basically used for sharing file and directory on windows and Linux machine. Using it you can share printers, files and directories on window machine and Linux machine.

Note -> Disabled Firewall

Note -> Before configuring the samba server first install the samba rpm package from using YUM or using rhel 5 DVD.

Using Yum -> yum -y install samba*

------------------------------------------------------------------------------
On Server Side

After installing of samba rpm, login as root and open the samba configuration file in editing mode. The configuration file is

vi /etc/samba/smb.conf

In /etc/samba/smb.conf file go to the line number 80 and edit it like that

host allow = 127. 192.168.1

Uncomment the line and leave it.


Now go to end of file and add these lines

[Test] # Here [Test] is shared filename of directory
comment # any thing you like
path=/home/linux # Here path is your shared directory
validuser=Michal # Michal is a user name through which you can access shared
directory on linux machine.
read list=Michal # Permission for reading directory for user Michal
write list=Michal # Permission for writing share director for user
Browsable=yes # Permission for browse samba share on clients end.

Save & Exit.

Now add a user as you define in /etc/samba/smb.conf configuration file. Here I use Michal

useradd michal
smbpasswd -a michal

Set user password.Remeber here I use "smbpasswd" not "passwd" to set password for Michal.Becaue samba server has its own file to save user passwd.Samba server retrieved the passwd information from smbpasswd file.

And on linux machine you have to must a user password to access shared directory using samba. Without it you can’t login.

----------------------------------------------------------------------------
Here I suggest you add user before configuring the /etc/samba/smb.conf file.
-----------------------------------------------------------------------------

*****************************************************************************

On client Side

To download file

smbclint -L //192.168.1.254 /test -U michal

mget filname -------> to download

mput filename -------> to upload

On Window Machine

Open--> run and the server ip address

\\192.168.1.254 press enter.

You can see only Share file name not the shared directory name.

***************************************************************************

Read more: http://networkupd8.blogspot.com/2010/11/samba-server-in-linux.html#ixzz1LHThMqrN

Wednesday, April 20, 2011

How To Install YUM Server in RHEL 6

Step By Step Configration of Yum Server
1. mount /dev/cdrom /mnt
2 rpm -ivh /mnt/Server/Packages/vsftpd*
3. cp -rv /mnt/* /var/ftp/pub/
4. rpm -ivh /mnt/Server/Packages/delta*
5. rpm -ivh /mnt/Server/Packages/Pythen-delta*
6. rpm -ivh /mnt/Server/Packages/createrepo*
7. vi /etc/yum.repos.d/server.repo
[yum-server]
name= This is my RPM store
baseurl=file:///var/ftp/pub/
enable=1
gpgcheck=0
8. createrepo -v /var/ftp/pub
9. rm -rf /var/ftp/pub/.olddata
10. yum clean all
11. yum update
Now Your Yum Server is Configured