Tuesday, June 28, 2011

Scientific Linux 6

Recently I start using Scientific Linux on KVM virtual hosts. For anyone new to Scientific its a Enterprise Linux based on RHEL just like Centos maintained by Fermi National Accelerator Laboratory and the European Organization for Nuclear Research 'CERN' - and RHEL, of course :)

Scientific Linux folks is closely following the upstream srpm provider (RHEL) and its already shipped with version 6 just like RHEL 6.

The other things which inspired me to give a try to Scientific Linux is the latest version of Linux Kernel with latest hardware support, the ext4 filesystem is the default, KVM enhancement, latest versions of software eg PHP, Mysql which means I don't have to mess around with test repos or yum priorities

For detail What's new in RHEL/Scientific Linux please refer to RHEL.

I encourage anyone interested in RHEL and/or building your own test server, to experiment with this distro.

Monday, June 20, 2011

Medialess installation of Redhat Enterprise 6/Centos/Scientic Linux 6

This procedure assumes you are already using Red Hat Enterprise Linux or another relatively modern Linux distribution, and the GRUB boot loader. It also assumes you are a somewhat experienced Linux user.

To perform medialess installation of Redhat Enterprise 6/Centos/Scientific Linux 6 without media or a PXE server, the system must have two files stored locally, a kernel and an initial RAM disk

Copy the vmlinuz and initrd.img files from a Red Hat Enterprise Linux DVD (or DVD image) to the /boot/ directory, renaming them to vmlinuz-install and initrd.img-install.

Editing the GRUB Configuration

The GRUB boot loader uses the configuration file /boot/grub/grub.conf. To configure GRUB to boot from the new files, add a boot stanza to /boot/grub/grub.conf that refers to them

title Installation
    root (hd0,0)
    kernel /boot/vmlinuz-install ip=xxx.xxx.xx.x netmask= gateway=xxx.xx.xx.x dns=xxx.xx.xx.x vnc vncpassword=qwerty repo=http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/ lang=en_US keymap=us
    initrd /boot/initrd.img-install

If using network interface other than eth0 then you must have to specify it with ksdevice=ethX, then the kernel line will read something like this for eth1

kernel /boot/vmlinuz-install ip=xxx.xxx.xx.x netmask= gateway=xxx.xx.xx.x dns=xxx.xx.xx.x ksdevice=eth1 vnc vncpassword=qwerty repo=http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/ lang=en_US keymap=us

The following options are generally useful for medialess installations:

IP = yourIP
netmas = Netmask
gateway = your Gateway
dns = your dns
vnc (for remote graphical installation)
vncpassword = Yourpassword
repo = Redhat/Centos/SL repo (In the sample I use the Scientific Linux 6 repo)

Also change the entry "default 0" to boot from new kernel entries, when done reboot the system.

Completing the installation:
From your local system use vncviewer to connect to the remote server and complete the installation process

$ vncviewer RemoteHostIP

Sunday, June 19, 2011

KVM virt-install: Install Scientific Linux 6 (RHEL6) as KVM Guest

Network installation of SL6 64bit as KVM guest.

virt-install --name se6 \
--ram 884 \
--os-type='linux' \
--disk path=/var/lib/libvirt/images/se6.img,size=10 \
--network network:default \
--accelerate \
--vnc \
--location http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/

Connect from your local system to continue the installation

virt-viewer -c qemu+ssh://root@IPAdress/system se6

Friday, June 17, 2011

Installing skype on Fedora 14 64bit

Skype only available for 32bit version of Fedora while most of the folks already get into wagon of 64bit OS, here is short howto installing the skype on 64bit Fedora. The hack is to install 32bit version of the following packages on 64bit Fedora.

yum install glibc.i686 alsa-lib.i686 libXv.i686 libXScrnSaver.i686 qt.i686 qt-x11.i686
Download Skype Fedora 13+ package from Skype official site http://www.skype.com/intl/en-us/get-skype/on-your-computer/linux/

And then install it.

yum install --nogpgcheck skype-

Hoping this is helpful