Space Science and Engineering CenterUniversity of Wisconsin-Madison

Virtual Machines: A method for distributing DB processing software

Liam Gumley

Space Science and Engineering CenterUniversity of Wisconsin-Madison

What is a Virtual Machine?

According to VMware:• “A virtualized x86 PC

environment on which a guest operating system and associated application software can run.”

• “Multiple virtual machines can operate on the same host machine concurrently.”

3Windows XPWindows XP

Linux Virtual MachineLinux Virtual Machine

SeaDASSeaDAS

Space Science and Engineering CenterUniversity of Wisconsin-Madison

The Players

• VMware, VirtualBox, and Parallels all support Windows, Linux, Mac host operating systems

• Just about any x86 OS is supported as a guest operating system (as a VM)

• VirtualBox is free for personal use

Note: Virtual PC (Microsoft) only supports Windows hosts and guests

Space Science and Engineering CenterUniversity of Wisconsin-Madison

Why are VMs relevant to DB?

1. All currently available DB processing packages are supported on Linux, e.g., IMAPP, DBCRAS, DBGE, SPAs, SeaDAS, HDFLook, etc.

2. Many users in DB land are still tied to Windows hosts for processing

3. VMs provide an easy way to provide a “ready to run” DB processing system

Space Science and Engineering CenterUniversity of Wisconsin-Madison

Typical DB install on Linux

1. Find a new or spare computer2. Install Linux3. Download DB software4. Install DB software5. Test DB software6. Set up data ingest7. Make sure 1-6 are documented

and repeatable

Space Science and Engineering CenterUniversity of Wisconsin-Madison

Typical DB VM install1. Find a Windows computer2. Install VMware player (free) 3. Download DB VM zip file4. Run VMware player

Space Science and Engineering CenterUniversity of Wisconsin-Madison

Advantages of a DB VM1. An expert can install and

configure Linux and all the necessary applications

2. End user has to invest only a small amount of time

3. The system can be restored to original state very easily (just download the VM zipfile again)

Space Science and Engineering CenterUniversity of Wisconsin-Madison

VM Features1. Networking configuration is

handled by the host, and via NAT in the VM: If Internet works in the host, it works in the VM

2. VM can share folders with the host: Input files can be dropped in a host directory (e.g., C:\MODIS)

3. VM can be suspended (like closing a laptop)