Our training courses use a live USB that includes the Ubuntu operating system installed with OpenFOAM and supporting software. Files created during the training are saved onto the USB device in a persistent manner, so the participant can retrieve them after the training. The device can be booted on a training room computer or a personal laptop, noting that the native operating system and hard drives are not used. The requirements for booting the live USB device on a computer are described below.
Computer BIOS
The computer BIOS must support booting from USB. Almost all modern computers do, the most notable exception being Intel-based Macintosh computers, which does not include a USB driver in the BIOS firmware. The limitation might be overcome by booting with the Unified Extensible Firmware Interface (UEFI) that links the platform firmware to the operating system, which can provide the USB driver. However, experience shows that the live USB does not always work in “UEFI” boot-mode. In general, it is more reliable to set the boot-mode to “legacy” in the BIOS settings. The BIOS must be able to boot as a general external USB hard drive, usually labelled in the boot options as USB-HDD. Other options, such as USB-ZIP or USB-FDD relate to old Iomega Zip and floppy drives respectively, which expect very specific disk partitioning, different from the live USB.
A promising option to boot a live USB on a Macintosh is to use the Mac Linux USB Loader software. We have not tested this ourselves, but have heard positive success stories.
Computer memory (RAM) requirements
Therefore the computers generally require 2GB of RAM to run the course successfully, since the live operating system occupies a reasonable amount of system RAM and some of the course exercises are reasonably memory-intensive. We have witnessed a strange phenomenon where writing data to the live USB was extremely slow when the machine RAM exceeded 16GB. Until we understand why this occurred, our recommendation is not to exceed 16GB.
Graphics card
The live operating system contains a variety of graphics card drivers to work on most hardware without installation of additional drivers. The video mode setting is built into the Linux kernel so that the splash screen renders nicely during boot. The downside is that if this does not work properly with a particular video card, you get a black screen. The workaround if this happens is to boot with nomodeset. This is selected by the F6 key when prompted to “press enter to boot…”
Processor (CPU)
Any modern CPU is sufficient to run the live USB effectively for the training. For example, a laptop running an Intel i3, dual-core 2GHz CPU is acceptable; an Intel i5, quad-core 3GHz CPU handles all computing demands comfortably.
Networking
Internet access is preferable, but not essential to the training.