Top 5 Open Source Linux Server Provisioning Software

Posted on in Categories Linux last updated August 10, 2010

Server provisioning is nothing but load the Linux or UNIX like operating systems automatically with actual operating systems, device drivers, data, and make a server ready for network operation without any user input. Typically you select a server from a pool of available servers, load the operating systems (such as RHEL, Fedora, FreeBSD, Debian), and finally customize storage, network (IP, gateway, bounding etc), drivers, applications, users etc. Using the following tools you can perform automated unattended operating system installation, configuration, set virtual machines and much more. These software can be used to install a lot (say thousands) of Linux and UNIX systems at the same time.

vSphere Web Access 503 Service Unavailable Error And Solution

Posted on in Categories vmware last updated May 21, 2010

By default vSphere does not provide client for Linux or OS X. You need to use Windows system to manage your VMware ESX server. However, it does provides vSphere Web Access which allows you to organize and share virtual machines using web browser. If you try to access vSphere Web Access you may get an error which read as follows:

503 Service Unavailable

You can fix this problem as follows.

Top 10 Linux Virtualization Software

Posted on in Categories Linux, Linux desktop, Linux distribution, Linux Scalability, Linux Virtualization, Networking, RedHat/Fedora Linux, Security, Solaris, Storage, Ubuntu Linux, UNIX, vmware, Windows server, xen last updated December 31, 2008

Virtualization is the latest buzz word. You may wonder computers are getting cheaper every day, why should I care and why should I use virtualization? Virtualization is a broad term that refers to the abstraction of computer resources such as:

  1. Platform Virtualization
  2. Resource Virtualization
  3. Storage Virtualization
  4. Network Virtualization
  5. Desktop Virtualization

This article describes why you need virtualization and list commonly used FOSS and proprietary Linux virtualization software.

Linux Xen High Availability Clusters Configuration Tutorial

Posted on in Categories File system, Hardware, High performance computing, Linux, Linux Scalability, Linux Virtualization, UNIX, Windows, xen last updated February 6, 2008

Xen is one of the leading Virtualization software. You can use Xen virtualization to implement HA clusters. However, there are few issues you must be aware of while handling failures in a high-availability environment. This article explains configuration options using Xen:

The idea of using virtual machines to build high available clusters is not new. Some software companies claim that virtualization is the answer to your HA problems, off course that’s not true. Yes, you can reduce downtime by migrating virtual machines to another physical machine for maintenance purposes or when you think hardware is about to fail, but if an application crashes you still need to make sure another application instance takes over the service. And by the time your hardware fails, it’s usually already too late to initiate the migration.

So, for each and every application you still need to look at whether you want to have it constantly available, if you can afford the application to be down for some time, or if your users won’t mind having to relogin when one server fails.

=> Using Xen for High Availability Clusters [onlamp.com]

Download of the day: Oracle VM

Posted on in Categories Download of the day, High performance computing, Linux, Linux distribution, Linux Virtualization, Networking, xen last updated December 7, 2007

Virtualization is the process of abstracting computing resources such that multiple operating system and application images can share a single physical server, bringing significant cost-of-ownership and manageability benefits. Through its Oracle VM product, Oracle offers scalable, low-cost server virtualization for heterogeneous applications.

Oracle VM is free server virtualization software that fully supports both Oracle and non-Oracle applications, and is three times more efficient than other server virtualization products.
Continue reading “Download of the day: Oracle VM”

Start and stop VMWARE VPS / virtual machine guest operating system from command line

Posted on in Categories Howto, Linux, Linux distribution, RedHat/Fedora Linux, Sys admin, Tips last updated June 30, 2007

Vmware server comes with the nifty vmware-cmd utility. It allows an administrator to perform various operations on a virtual machine from Linux command line / shell prompt such as:

=> Stop / Start VM

=> Get VM status

=> Setup variables

=> Powerdown VM and much more

Task: Lists the virtual machines on the local server

You can list all servers and config file, enter:
# vmware-cmd -l
Output:

/nas/vms/Ubuntu/Ubuntu.vmx
/nas/vms/FreeBSD/FreeBSD.vmx
/nas/vms/OpenBSD/OpenBSD.vmx
/nas/vms/Debian4/Debian4.vmx
/nas/vms/CentOS5/CentOS5.vmx

Turn on VM / Power up VPS

Just pas start option to vmware-cmd,
# vmware-cmd /nas/vms/FreeBSD/FreeBSD.vmx start

To stop VM/VPS, enter:
# vmware-cmd /nas/vms/FreeBSD/FreeBSD.vmx stop

To reset VM/VPS, enter:
# vmware-cmd /nas/vms/FreeBSD/FreeBSD.vmx reset

To suspend VM/VPS, enter:
# vmware-cmd /nas/vms/FreeBSD/FreeBSD.vmx suspend

Find out if OpenBSD VM is on or off:
# vmware-cmd /disk2.vmware/vms/OpenBSD/OpenBSD.vmx getstate
Output:

getstate() = off

vmware-cmd offers other options, please consult VMWARE documentation for more information.

What Is /dev/shm And Its Practical Usage

Posted on in Categories Linux last updated March 14, 2006

/dev/shm is nothing but implementation of traditional shared memory concept. It is an efficient means of passing data between programs. One program will create a memory portion, which other processes (if permitted) can access. This will result into speeding up things on Linux.