I recently used a Live CD to resolve a file access issue on a .7z archive. I am a new Linux user and initially concluded that I could not install p7-Zip (or other software) in a live session. I later discovered that the Install button in the Software Manger GUI is hidden until you press More Info... . I was very happy, but I later wondered where the OS and programs do their writes. It seems clear that RAM is employed; I am hoping to get some details on Ubuntu's implementation (if a RAMDisk is used) and how much space is allocated. (Note that this is a different idea from persistent storage on a USB drive or RW optical media). Thank you kindly for reading and in advance for discussion!
1 Answer
It is true that you can install software in a live session of Ubuntu, when booting from a USB stick (called a Live CD). Where it stores it depends on which kind of USB stick you have made (persistent or non-persistent, as you mention yourself). To provide a complete answer, I will mention both options below.
If the standard, non-persistent session is used, it makes a file system in the RAM, which can be used until RAM space runs out. All changes will be deleted when rebooting the system.
What can also be done though is to use a persistent USB drive, where a certain amount of space is allocated on the USB drive itself. This space can be used for saving configurations and installed software and save it, making it available again when booting from the USB next time.