Monday, May 24, 2010

How to install and configure Linux-HA high avaliability heartbeat - 3.0 cluster on redhat rhel5


Heartbeat is a High Availabily cluster software in linux platform. Here we will discuss how to
install and configure heartbeat-3.0.3 in redhat enterprise linux. In this example we will configue
a webserver using apache and we will cluster it. It can be implemented on centos, fedora and other redhat flavors.
Heartbeat Version is : heartbeat-3.0.3
2 linux nodes, rhel5.4.
LAN & Internet connection.
A yum server.

Tuesday, May 18, 2010

How to install and configure Openfiler iscsi target


Openfiler is a os / sw for implementing or configuring iscsi devices. Suppose your company doesnt have a SAN storage. But you want a shared disk for one application. You can use openfiler here. With openfiler you can create a iscsi target. And by installing the proper iscsi initiator on the client you can mount the openfiler's iscsi target on your client. In background its just redhat rhel linux.
Iscsi-initiator [client]        <----------------------------------         Openfiler Iscsi-target
In this example we are using openfiler as iscsi target and a Rhel5 machine as iscsi initiator.
Openfiler Installation and configuration:
Download the openfiler openfiler-2.3-x86-disc1.iso from Openfiler website. Installation steps are shown below.

Wednesday, May 12, 2010

How to attach or search a iscsi target device to a Linux machine


 To attach or search a iscsi target your machine should be configured as an iscsi initiator. There is a software in linux called iscsi-initiator-utils. You can either use rpm or compile the source to install it.

 #rpm -ivh iscsi-initiator-utils-

 After installing iscsi-initiator-utils package, start the iscsid service. And set the chkconfig entry so that it will automatically start at the next reboot.

 # service iscsid start
 Turning off network shutdown. Starting iSCSI daemon: [ OK ]
 [ OK ]

 # chkconfig iscsid on
# chkconfig iscsi on

Searching the iscsi target:

# iscsiadm -m discovery -t sendtargets -p
You can also use port number if you want. As follows

# iscsiadm -m discovery -t sendtargets -p,1

You will get the scanned result as the line above.

Loging in to the iscsi target:

# iscsiadm -m node -T,1 -p -l

#fdisk -l
will list the iscsi targets now.

Best Reads:
1.  iSCSI: The Universal Storage Connection: The Universal Storage Connection
2.  Storage Networks Explained: Basics and Application of Fibre Channel SAN, NAS, iSCSI, InfiniBand and FCoE

Saturday, May 8, 2010

Download Red Hat Enterprise Linux 6 Beta


Redhat releases its Red Hat Enterprise Linux 6 Beta last month and its available for download now. Redhat says the following things are the major features of Red Hat Enterprise Linux 6 Beta.

[From their site]

Power management: tickless kernel and improvements through the application stack to reduce wakeups, power consumption measurement by Powertop, Power Management (ASPM, ALPM), and adaptive system tuning by Tuned, all enhance more efficient system power usage
Next generation networking: comprehensive IPv6 support (NFS 4, CIFS, mobile support [RFC 3775], ISATAP support), FCoE, iSCSI, and a new and improved mac 802.11 wireless stack.

Reliability, availability, and serviceability (RAS): system-level enhancements from industry collaborations make the most of hardware RAS capabilities and NUMA architectures.

Fine-grained control and management: improved scheduler and better resource management in the kernel via Completely Fair Scheduler (CFS) and Control Groups (CG).

Scalable filesystems: ext4 file system provides support for larger file sizes and significantly reduces repair times over ext3. XFS® is a high-performance file system that supports extremely large files and is optimized for large data transfers.

Virtualization: KVM includes performance improvements and new features, sVirt protects the guest and host from unauthorized access, SR-IOV and NPIV deliver high-performance virtual use of physical devices, and libvirt leverages kernel resource management functionality.

Enterprise security enhancement: SELinux includes improved ease of use, application sandboxing, and significantly increased coverage of system services, while SSSD provides unified access to identity and authentication services as well as caching for off-line use.

Development and runtime support: SystemTap improvements, ABRT is a new framework for simple collection and reporting of bug information, and improvements are made to GCC (version 4.4.3), glibc (version 2.11.1), and GDB (version 7.0.1).

You can download the ISO here
It needs a email submission. Thats all. Enjoy

Thursday, May 6, 2010

How to install and configure NIS server in redhat linux rhel5 / Centos



NIS is centralized authentication software in Linux / Unix / Solaris platform. In a network, there will be a NIS server, one or more NIS slaves and lots of NIS Client machines. This document explains how to install and configue NIS Server or Master, Slave and Client Machines in Redhat enterprise linux rhel5. It can also be applicable on centos, fedora and other variants.
Configuring the NIS MASTER Server:
Packages :
For installing NIS the following packages are required.
For server:

For client: