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;
# }
#}

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

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