LiveUSB

Preamble

Revision 55555 of ReactOS introduced support for USB devices, and after some time it became possible to run the OS from a USB drive. In revision 55714 ReactOS was successfully installed and running from Patriot Xporter XT 8Gb USB stick. LiveCD revision 55995 has also been successfully executed from the same device using USB 1.1 OHCI.

Note: To install on a USB-HDD, it is preferable to use Bootcd; and for a USB flash drive, it is preferable to use LiveCD. Differences between installing on USB-HDD or USB flash drive are minor, but keep in mind that the resources (speed and storage space) of a USB flash drive can be much more limited than those of a hard drive. Flash drives also often have a limited lifetime of read and writes before they become damaged or unusable.

For more convenient use or testing of LiveUSB mode, you need to know the following things:

• If you install bootcd, the first phase of installation to a virtual HDD in a virtual machine is much faster than directly to the USB-stick. Therefore later in this article we will consider how to transfer files needed to start the second phase of the installation from a virtual machine to a flash drive/USB-HDD.
• If you install ReactOS to a USB-drive and install the MBR/VBR using the installer (without formatting the disk), then it is likely that the system will be unable to boot. If you wish to boot more than just ReactOS from a USB drive, please refer to the second paragraph of this article.

Installing the system to a USB-drive

Transferring files from VM to USB-drive

First of all, you need to install and run on your computer a virtual machine that supports virtual hard disks format vmdk. These VMs are, for example, VirtualBox and VMWare Player. Then, install ReactOS in a virtual machine, then close the VM. Next, you need to download the command-line utility VMWare Disk Mount Utility Go using command line to the program's folder and execute:

vmware-mount x: path_to_the_vmdk_file

Copy the files from mounted drive to USB-Drive

Disassemble the image using next command:

vmware-mount / d x:

Note: If you want to use other formats of virtual hard disks, then you have to use other similar utilities.

Installing the MBR

To load ReactOS you can use Grub4Dos. Get the latest version of the archive GRUB, as well as GUI installer.

• Extract the installer, copy to its folder files from GRUB package.
• Run the GRUB GUI, choose from the disk list your USB flash drive (if you're using Windows, then the number can be found in the Disk Manager). Click to install. Close the window with the message about successful installation.
• Copy file called "grub" to your USB drive.
• If a partition on a flash drive is not active, then make it activeusing any partition management utility.
• Create a menu.lst using next template:

color blue/green yellow/red white/magenta white/magenta
timeout 30
default/default

title ReactOS
root (hd0, 0)
kernel/freeldr.sys

title ReactLive
root (hd0, 0)
kernel/loader / setupldr.sys

title reboot
reboot

Done.

Try to boot. If it doesn't work (damn) it could be either due to a bug in the USB driver or because the system regression (or regression of driver). Try to use working revision (check the beginning of the article). If they work then you're dealing with regression. Please report about it to developers. If they also do not work then your USB controller or USB drive is not yet supported. Please report this too as new bug.

References

• Boot FreeLoader from GRUB