Wednesday, September 26, 2012

NTP Server Configuration in RHEL 6

This video explains how to setup the local NTP server in Red Hat Enterprise Linux 6.

Client Side configuration:
Step 1: Set the ipaddress in the same range (say 9.0.0.21) & check up with ping command.
Step 2: #system-config-date
            Remove all and give 9.0.0.20 (NTP server ip) in NTP Servers box.
Step 3: #service ntpd restart
Step 4: #chkconfig ntpd on
Step 5: #ntpdate -b 9.0.0.20
Note: The time will be synchronized with the NTP server, the client system restart requires sometimes.

Wednesday, September 12, 2012

Pre requestis for Red Hat Certified Engineer — RHCE


An RHCE® certification is earned by a Red Hat® Certified System Administrator (RHCSA) who has demonstrated the knowledge, skill, and ability required of a senior system administrator responsible for Red Hat Enterprise Linux® systems. Professionals holding this certification have continually helped their companies with successful deployments and migrations.
Prerequisites
An RHCE is able to perform the following tasks (in addition to tasks associated with RHCSA):
    Configuration of static routes, packet filtering, and network address translation
    Setting kernel runtime parameters
    Building simple RPMs
    Configuring an iSCSI initiator
    Producing and delivering reports on system utilization
    Using shell scripting to automate system maintenance tasks
    Configuring system logging, including remote logging
    Configuring a system to provide networking services, including HTTP/HTTPS, FTP, NFS, SMB, SMTP,  SSH, and NTP
Hiring IT professionals who are certified as RHCEs allows many organizations to increase their ratio of servers to administrators, enabling them to be more cost effective in building out their infrastructures without needing to bring on additional resources.

Exam objectives


RHCE exam candidates should consult the RHCSA exam objectives and be capable of RHCSA-level tasks, as some of these skills may be required in order to meet RHCE exam objectives. Red Hat reserves the right to add, modify, and remove objectives. Such changes will be made public in advance through revisions to this document.

RHCE exam candidates should be able to accomplish the following without assistance. These have been grouped into several categories.

System configuration and management
    Route IP traffic and create static routes.
    Use iptables to implement packet filtering and configure network address translation (NAT).
    Use /proc/sys and sysctl to modify and set kernel runtime parameters.
    Configure a system to authenticate using Kerberos.
    Build a simple RPM that packages a single file.
    Configure a system as an iSCSI initiator that persistently mounts an iSCSI target.
    Produce and deliver reports on system utilization (processor, memory, disk, and network).
    Use shell scripting to automate system maintenance tasks.
    Configure a system to log to a remote system.
    Configure a system to accept logging from a remote system.

Network services
Network services are an important subset of the exam objectives. RHCE candidates should be capable of meeting the following objectives for each of the network services listed below:
    Install the packages needed to provide the service.
    Configure SELinux to support the service.
    Configure the service to start when the system is booted.
    Configure the service for basic operation.
    Configure host-based and user-based security for the service.

HTTP/HTTPS
    Configure a virtual host.
    Configure private directories.
    Deploy a basic CGI application.
    Configure group-managed content.

DNS
    Configure a caching-only name server.
    Configure a caching-only name server to forward DNS queries.
    Note: Candidates are not expected to configure master or slave name servers.

FTP
    Configure anonymous-only download.

NFS
    Provide network shares to specific clients.
    Provide network shares suitable for group collaboration.

SMB
    Provide network shares to specific clients.
    Provide network shares suitable for group collaboration.

SMTP
    Configure a mail transfer agent (MTA) to accept inbound email from other systems.
    Configure an MTA to forward (relay) email through a smart host.

SSH
    Configure key-based authentication.
    Configure additional options described in documentation.

NTP
    Synchronize time using other NTP peers.

Installation Server works good in RHEL5.3

You can install RHEL6.1 from the RHEL5.3 installation server itself.

1. Create a PXE server. (Refer the blog)
2. Copy all DVD content to /var/ftp/pub/rhel6.1 location
3. Copy the important files vmlinuz & initrd  into the /tftpboot/rhel6.1 location
4. Create kickstart file using system-config-kickstart.
5. Edit the file "/tftpboot/pxelinux.cfg/default" as follows
label 6.1
  kernel rhel6.1/vmlinuz
  append initrd=rhel6.1/initrd.img ks=nfs:192.168.0.254:/var/ftp/pub/rhel6.1/ks.cfg

6. Type 6.1 in the PXE Server boot screen.

RHEL6.1 Kickstart file


The following file is the kickstart file for installing RHEL6.1

#platform=x86, AMD64, or Intel EM64T
#version=DEVEL
# Firewall configuration
firewall --disabled
# Install OS instead of upgrade
install
# Use NFS installation media
nfs --server=192.168.0.254 --dir=/var/ftp/pub/rhel6.1
# Root password
rootpw --iscrypted $1$x7Z15vjx$hG7xzuDLfLbCqgvxiazDx.
# System authorization information
auth  --useshadow  --passalgo=sha512
# Use text mode install
text
firstboot --disable
# System keyboard
keyboard us
# System language
lang en_US
# SELinux configuration
selinux --enforcing
# Installation logging level
logging --level=info
# Reboot after installation
reboot
# System timezone
timezone --isUtc Asia/Kolkata
# System bootloader configuration
bootloader --location=mbr --md5pass="$1$phl5jhIB$vIl45UqkSrUgZnUxdyySw."
# Partition clearing information
clearpart --all  
# Disk partitioning information
part / --fstype="ext4" --size=10000
part /home --fstype="ext4" --size=1024
part swap --fstype="swap" --size=1024

%packages
@additional-devel
@backup-client
@backup-server
@base
@cifs-file-server
@client-mgmt-tools
@compat-libraries
@console-internet
@core
@debugging
@basic-desktop
@desktop-debugging
@desktop-platform
@desktop-platform-devel
@development
@dial-up
@directory-client
@directory-server
@mail-server
@eclipse
@emacs
@identity-server
@ftp-server
@fonts
@general-desktop
@graphical-admin-tools
@graphics
@hardware-monitoring
@ha
@ha-management
@infiniband
@input-methods
@internet-browser
@java-platform
@kde-desktop
@large-systems
@legacy-unix
@legacy-x
@load-balancer
@mainframe-access
@system-management-messaging-client
@mysql-client
@mysql
@nfs-file-server
@network-server
@storage-server
@network-file-system-client
@network-tools
@php
@performance
@perl-runtime
@postgresql-client
@postgresql
@print-server
@print-client
@remote-desktop-clients
@resilient-storage
@system-management-snmp
@scientific
@security-tools
@server-platform
@server-platform-devel
@server-policy
@storage-client-multipath
@system-management
@system-admin-tools
@system-management-messaging-server
@tex
@technical-writing
@turbogears
@virtualization-client
@virtualization-platform
@web-server
@web-servlet
@system-management-wbem
@x11
@storage-client-iscsi
libXinerama-devel
xorg-x11-proto-devel
startup-notification-devel
libgnomeui-devel
libbonobo-devel
junit
libXau-devel
libgcrypt-devel
popt-devel
libdrm-devel
libXrandr-devel
libxslt-devel
libglade2-devel
gnutls-devel
mtools
pax
python-dmidecode
oddjob
sgpio
genisoimage
wodim
abrt-gui
qt-mysql
desktop-file-utils
ant
rpmdevtools
jpackage-utils
rpmlint
krb5-pkinit-openssl
certmonger
openldap-clients
pam_krb5
krb5-workstation
ldapjdk
samba
krb5-server-ldap
krb5-server
slapi-nis
netpbm-progs
ImageMagick
telnet
tcp_wrappers
xterm
xorg-x11-xdm
libXmu
perl-DBD-MySQL
dnsmasq
radvd
sg3_utils
perl-DBD-SQLite
perl-Mozilla-LDAP
rdesktop
atlas
numpy
hmaccalc
ipmitool
pexpect
crypto-utils
libvirt-java
mod_auth_kerb
mod_nss
certmonger
perl-CGI
mod_revocator
tog-pegasus
%end

Tuesday, September 11, 2012

How to install Mate desktop in Ubuntu 12.04

To install Mate desktop in Ubuntu open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

  • sudo add-apt-repository "deb http://packages.mate-desktop.org/repo/ubuntu precise main"
  • sudo apt-get update
  • sudo apt-get install mate-archive-keyring
  • sudo apt-get update
  • sudo apt-get install mate-core
  • sudo apt-get install mate-desktop-environment

Tuesday, September 4, 2012

Password to boot Red Hat Enterprise Linux 6

This video explains how to set the password in the grub boot loader. The password will be asked to boot the OS always.

Saturday, September 1, 2012

Set the password for Grub file in Red Hat Enterprise Linux 6

This video explains how to set up the password for grub.conf file.