During my time as the technical officer for CAIRSS, I have discovered tools that have increased the efficiency of services provided to the CAIRSS community. I presented a powerpoint presentation at the 2010 CAIRSS community day in Melbourne. During the presentation I briefly introduced some nice, efficient tools. The presentation given on the day was aimed mainly at technical staff. This blog post is aimed at a wider audience including repository managers and technical staff1. This second post in the series “Introducing nice, efficient tools” covers the topic of virtual servers. Virtual servers can be employed for a range of tasks including the development, installation, configuration and testing of institutional repositories.
Virtual machines
“A virtual machine (VM) is a software implementation of a machine (i.e. a computer) that executes programs like a physical machine” (Virtual machine – Wikipedia 2011). A virtual machine is software and therefore does not have any physical components per se. The installation of virtual server software such as VMmware or VirtualBox is required on a physical machine (host) in order for virtual machines (guests) to be created.
One of the advantages of using virtual machines is that additional physical hardware is not required each time a virtual machine is created. Using virtual machines minimises costs and delays relating to hardware procurement.
A use case for a virtualization in the repository space may be a technical officer using a Windows machine who requires a Linux environment in order to install, configure and experiment with the EPrints software. The technical officer in this case would be able to install virtual server software like VMware on the Windows machine and then create a Linux virtual machine where EPrints could be installed.
Virtual appliances
A virtual appliance is essentially a virtual machine with a specialised software application pre installed and configured for use. A good example of this is the DSpace virtual appliance available at JumpBox which contains a complete DSpace installation that can be used within VMware, Parallels, VirtualBox and Amazon EC2 host environments.
There are also a large number of appliances available which provide turn key solutions to database instances and cloud storage which may be of interest, even if just for testing and development purposes. You can browse some of the many virtual appliances at the following locations VMware appliances and VirtualBox appliances.
Virtualization at your institution
Issues to consider when creating guests on a physical host within an institution include the following;
- Guest IP address allocations – are there extra IP addresses available where the host resides?
- Concerns over the use of non standard operating system/machine images – new machines that are commissioned generally must confirm to the policies outlined by the IT department.
- Concerns over internal network and internet security requirements – machines created by individual users and not by IT systems administrators may pose a security risk to the neighboring machines and networks depending on how the network is configured.
Cloud computing
Cloud computing takes virtualization one step further by providing off site hosting. Examples of cloud computing companies include GoGrid, Amazon EC2 and RackSpace. There are quite a few tools available that assist in creating and maintaining virtual servers in the cloud. A particular tool that I use on a regular basis is called Elastifox. Elastifox allows you to create new Amazon virtual machines, assign IP addresses and storage allocations and administer security settings… all within your browser.
If you would like any further information on this topic please leave a comment or email cairss-technical@caul.edu.au
List of References
Virtual machine – Wikipedia, the free encyclopedia. Available at: http://en.wikipedia.org/wiki/Virtual_machine [Accessed January 27, 2011].
