Pages

Tuesday, September 18, 2012

Setting DNS server@RHEL,fedora

#Packages needed are bind and bind-chroot
#1.install needed packages
yum -y install bind

#2.Configuration files are
rpm -qc bind

echo "The configuration files we use are"
echo "/etc/named.conf"
echo "/etc/named.rfc1912.zone"
echo "/var/named/named.localhost"
echo "/var/named/named.loopback"

#3. Opening the /etc/named.conf file for Editing
echo "EDIT THE
line no 11 -listen-port to any
line no 17 -allow-query to any"

vim /etc/named.conf

#4. Expalin the foward and reverse zone file in /etc/named.rfc1912.zones

echo "zone \"example.com\" IN {
type master;
file \"forward.zone\";
allow-update { none; };
};" >> /etc/named.rfc1912.zones


echo " zone \"122.168.192.in-addr.arpa\" IN {
type master;
file \"reverse.zone\";
allow-update { none; };
};" >> /etc/named.rfc1912.zones

vim /etc/named.rfc1912.zones
#5.make the copy of named.localhost as forward.zone

cp /var/named/named.localhost /var/named/forward.zone


#6.make the copy of named.loopback as reverse.zone

cp /var/named/named.loopback /var/named/reverse.zone


#7. Edit /var/named/forward.zone to get ip to host name resolution

echo "
@ IN SOA server.example.com. root.server.example.com. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
IN NS server.example.com.


server IN A 192.168.122.1
client IN A 192.168.122.25" >> /var/named/forward.zone

vim /var/named/forward.zone

#8. Edit /var/named/reverse.zone to get host name to ip resolution

echo "
@ IN SOA server.example.com. root.server.example.com (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
IN NS server.example.com.


1 IN PTR server.example.com.
25 IN PTR client.example.com. " >> /var/named/reverse.zone

vim /var/named/reverse.zone

#9.changing the group of forward and reverse zone to named

chgrp named /var/named/reverse.zone /var/named/forward.zone

#10. Service restarting and chkconfig on

service named restart
chkconfig named on

Monday, September 17, 2012

Setting DHCP server in rhel ,fedora

#Steps to Configure dhcp...
#First give static ip for the server machine ie dhcp server

#1.Packages needed
#-dhcp-

yum -y install dhcp

#2.Copying the config file from
#    /usr/share/doc/dhcp*/dhcpd.conf to /etc/dhcp/dhcpd.conf
echo "Configuration files are"
rpm -qc dhcp

cp /usr/share/doc/dhcp-4.1.1/dhcpd.conf.sample /etc/dhcp/dhcpd.conf

echo "Configuration Files Copied"

#3.Opening the config file
vim /etc/dhcp/dhcpd.conf

#4.Starting and Chkconfig the service . After adding needed subnetworks

service dhcpd start
chkconfig dhcpd on

echo "Service started and chkconfig is on"

############################################################################
# dhcpd.conf file
#
# Sample configuration file for ISC dhcpd
#

# option definitions common to all supported networks...
#############option domain-name "example.com";
#option domain-name-servers ns1.example.org, ns2.example.org;

##############default-lease-time 600;
##############max-lease-time 7200;

# Use this to enble / disable dynamic dns updates globally.
#ddns-update-style none;

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
###############authoritative;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
################log-facility local7;

# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.

#subnet 10.152.187.0 netmask 255.255.255.0 {
#}

# This is a very basic subnet declaration.

##############subnet 192.168.122.0 netmask 255.255.255.0 {
################  range 192.168.122.10 192.168.122.250;
#  option routers rtr-239-0-1.example.org, rtr-239-0-2.example.org;
################}

# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.

#subnet 10.254.239.32 netmask 255.255.255.224 {
#  range dynamic-bootp 10.254.239.40 10.254.239.60;
#  option broadcast-address 10.254.239.31;
##  option routers rtr-239-32-1.example.org;
#}

# A slightly different configuration for an internal subnet.
#subnet 10.5.5.0 netmask 255.255.255.224 {
#  range 10.5.5.26 10.5.5.30;
#  option domain-name-servers ns1.internal.example.org;
#  option domain-name "internal.example.org";
#  option routers 10.5.5.1;
#  option broadcast-address 10.5.5.31;
#  default-lease-time 600;
#  max-lease-time 7200;
#}

# Hosts which require special configuration options can be listed in
# host statements.   If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.

#host passacaglia {
#  hardware ethernet 0:0:c0:5d:bd:95;
#  filename "vmunix.passacaglia";
#  server-name "toccata.fugue.com";
#}

# Fixed IP addresses can also be specified for hosts.   These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP.   Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.
#host fantasia {
#  hardware ethernet 08:00:07:26:c0:a5;
#  fixed-address fantasia.fugue.com;
#}

# You can declare a class of clients and then do address allocation
# based on that.   The example below shows a case where all clients
# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.

##class "foo" {
#  match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#}
#
#shared-network 224-29 {
#  subnet 10.17.224.0 netmask 255.255.255.0 {
#    option routers rtr-224.example.org;
#  }
#  subnet 10.0.29.0 netmask 255.255.255.0 {
#    option routers rtr-29.example.org;
#  }
#  pool {
#    allow members of "foo";
#    range 10.17.224.10 10.17.224.250;
#  }
#  pool {
#    deny members of "foo";
#    range 10.0.29.10 10.0.29.230;
# }
#}

Wednesday, July 25, 2012

Creating local directory for yum installation using createrepo @ rhel ,fedora

To create a local directory from which we can install through yum,Mainly we need the "createrepo plugin of yum"

first make the directory

>mkdir pak

then copy the rpms into the directory

then use createrepo to create the repository files inside the folder

>createrepo pak

then it will make repository files and show following on success

Saving Primary metadata
Saving file lists metadata
Saving other metadata

then make a file @ /etc/yum.repos.d/pak.repo

>vim /etc/yum.repo.d/pak.repo

inside that we need name url and enable option
enable should be equal to 1 to make the repository
active all the time.the url will have destination to
the folder

as follows


[pal]
Name=pak $releasever $basearch local repository
baseurl=file:///pak
enabled=1

Sunday, July 22, 2012

fedora 17 and grub2

Fedora 17 and grub2...While installing fedora 17 from the live cd  at the end of finishing the installations i got an error like "installing bootloader failed ..system any not boot properly " the problem was maily with grub2 version .Even though the grub2 is much better than the older one it has some bugs .it shows some problem whiling installing to a system with older grub.

We can try reinstall the grub with the distro dvd rescue mode...

1.chroot  /mnt/sysimage

the root file system will be loaded to /mnt/image

2. grub2-install /dev/sda
installing the grub to ur harddisk ..in normal mode this wont work we should also give --force and --recheck

grub2-install --force --recheck /dev/sda

3.to get all the operating system use

grub2-mkconfig -o /boot/grub2/grub.cfg

the -o will create the config file

 

 

Saturday, July 14, 2012

To create keyboard shortcut for terminal in linux

open the terminal then type

>gnome-keybinding-properties

Then an window will pop up that window can be used to create custom keyboard shortcuts.

Click add and give name for the entry and terminal command which should be activated with shortcut and click Apply

now in the window backward an entry such as custom entry will appear and now click in shortcut then the disabled option changes to New shortcut .now press the needed shortcut it will be set.

command for terminal is gnome-terminal and give needed shortcuts

Resizable linux partions --LVM-logical volume management

In linux we can can create resizable partition  which can be resized if free space is available. That type of partitions logical volumes.
lvm-digram

1.-------->First we need to create normal logical partitions.
i have a partion  /dev/sda4  in /dev/sda
2.--------->Then we need to select the partition and change the partition type to 0x8e or create the partition as physical volume using given option in palimpsest
using fdisk command we could change the partion type to 0x8e . we could use the 't' option in fdisk to change the type ,after seleting the 't' option it will prompt for the partition no of which type need to be changed .using the 'l' option will list types of  partition type.
fdisk /dev/sda
At the Linux fdisk command prompt,

  1. press n to create a new disk partition,

  2. press p to create a primary disk partition,

  3. press 1 to denote it as 1st disk partition,

  4. press ENTER twice to accept the default of 1st and last cylinder – to convert the whole secondary hard disk to a single disk partition,

  5. press t (will automatically select the only partition – partition 1) to change the default Linux partition type (0×83) to LVM partition type (0x8e),

  6. press L to list all the currently supported partition type,

  7. press 8e (as per the L listing) to change partition 1 to 8e, i.e. Linux LVM partition type,

  8. press p to display the secondary hard disk partition setup. Please take note that the first partition is denoted as /dev/hdb1 in Linux,

  9. press w to write the partition table and exit fdisk upon completion.


3.-------->Next, this LVM command will create a LVM physical volume (PV) on a regular hard disk or partition:
pvcreate /dev/sda4

4---------->Now, another LVM command to create a LVM volume group (VG) called vg0 with a physical extent size (PE size) of 16MB:
vgcreate -s 16M vg0 /dev/hdb1

 

5---------->Create a 400MB logical volume (LV) called lvol0 on volume group vg0:
lvcreate -L 400M -n lvol0 vg0

This lvcreate command will create a softlink /dev/vg0/lvol0 point to a correspondence block device file called /dev/mapper/vg0-lvol0.

6----------->Formatting the partition to the needed type ..here i am going to format it to ext4 type

mkfs.ext4 /dev/vg0/lvol0
Finally mounting the partition to the needed place.here i will be mounting the partition to /data

mkdir  /data

mount /dev/vg0/lvol0 /data

some of the useful commands in this are

pvs

vgs

lvs

pvdisplay

vgdisplay

lvdisplay

more useful commands are lvextend and lvreduce

reduced should be used carefully because  cutting of the file system may cause data loose if not done properly

Tuesday, June 19, 2012

Gcc for windows-Install the MinGW (GCC) Compiler Suite and Cygwin prompt

This Gcc compiler doesn't exactly replaces the normal Linux gcc compiler .First download the file from following link and run it to install MinGW (Minimalist GNU for Windows).We need net connection to install this

http://sourceforge.net/projects/mingw/files/MinGW/





in latest MinGW you will have c compiler in the list .Select the needed components and select the path to which you need to install it.After the installation we need to set the environment .

Create a directory (e.g. C:\MinGW), download all packages to C:\MinGW, extract the files from each package, and add C:\MinGW\bin; to your PATH environment variable using C:\> set PATH=C:\MinGW\bin;%PATH%" .or set it normally with properties of mycomputer>Environment variables.

To get more linux effect in windows install Cygwin from http://www.cygwin.com/install.html to get a terminal effect.and install needed packages as needed in cygwin.to install cygwin also we need internet connection

http://www.eecg.utoronto.ca/~aamodt/ece242/cygwin.html