Live USB is a good way of testing out Linux distro without making changes to your computer. Unknown to many, there is a data persistency mode in the Live session where you can make changes and save files to your USB drive and the data will persist even after shutting down the live session. After testing out the live session, you can also install the distro to your USB drive instead of the internal hard drive. Both methods allow you to boot Linux from a USB drive and save data to it. So what are the differences between the two and which one should you use?
Live Session with Data Persistency
When you create a Live USB, presumably using the Startup Disk Creator tool, there is an option for you to choose how much space you want to reserve for storing of data.
What happen is that when you boot up the USB into the Live session, and make changes to the system, such as download a file, run the system update, install an application etc, your data will be saved to the reserved space in the USB drive. Data saved in this reserved space won’t be deleted when you shut down the live session. The next time you boot into the live session, you are still able to access and retrieve the data.
Advantages of Data persistency in Live Session
1. The main advantage of a Live USB is that it doesn’t need a lot of storage space. You can easily create a Live USB with data persistency with a 2GB USB drive while a full installation will require at least 8GB of storage space.
2. A Live USB is configured to run on almost all desktops and has a great compatibility with various hardware. If you want to test the Linux distro on various computers, using a Live USB with data persistency is the best way to do it.
Disadvantages of Persistent Live USB
1. The main disadvantage of a Persistent Live USB is the security issue. When you boot up a live USB, it boots directly to the desktop. There is no login or any security mechanism to protect anyone from accessing your data. The live USB is meant for you to test the distro and install it to the hard drive if you like it. It is not meant to be used as a production OS.
2. Slower boot up time. On bootup, the Live USB has to run a series of compatibility test to make sure that it can run well on the machine. This slows down the boot up time greatly.
3. The Linux distro in the live USB is outdated. Most Linux distros have their own update manager that can automatically update itself to the latest version. The Linux distro you are running in the USB is created from the ISO image which is often the release version, not the updated version. While you can technically run a system update in the live session to upgrade it to the latest version, there is a high chance that it might break the system because of a conflict in kernel and the bootloader is not configured to make use of the new updated kernel.
Full Installation of Linux on USB drive
A full installation of the distro onto the USB will perform just like any other desktop Linux, except that the core files now reside in the USB drive instead of the internal hard drive. It is not recommended to install a heavy distro, such as Ubuntu and Linux Mint, on the USB drive as it requires a large storage space. Distro such as the Precise Puppy is best suited to be installed in the USB.
Advantages of Full Install USB
1. A more secure system. You are required to login before you can use it and password is required to run any administrative task.
2. Faster bootup. A full Linux installation on USB is known to boot up much faster than a live USB.
Disadvantages of Full Install USB
1. Most Linux distro required a minimum of 8GB of storage space to install. However, as USB drive get bigger (in storage) and cheaper, this is becoming less of an issue.
2. Hardware compatibility. When you do a full installation, the installer will customize the system to work well with the current set of hardware. This means that if you use the full install USB on another computer, especially one that uses proprietary video driver, chances are that your Linux won’t run well.
When you are testing out the Linux distro, or are using the live USB as a rescue disk, then it is useful to make use of the data persistency feature in the live session. Other than that, it is not advisable to use the Live USB as the production OS.
Let us know what you think about this.
Image credit: USB flash drive stick being connected to laptop computer by BigStockPhoto