In the old days we could burn an Ubuntu or any Linux installation iso image onto a DVD-R, and then install it to our PC or as a virtual PC.
But since DVD drives are not present in many PCs nowadays, and the USB flash drives have gotten faster, can we burn the installation image on one USB flash drive, plug in another USB flash drive, install Ubuntu on that second USB flash drive and use it to boot up Ubuntu for common daily use?
>Solution :
Ubuntu installed on a flash drive, either "frugal" install (running direct from compressed ISO image) or full install has been a common way to carry Ubuntu along for years, even before USB ports and thumb drives got fast enough to start to compete with older platter drives for access time and transfer rate.
I’ve done this, and it does work, though unless I need to be able to start any computer I might run across in Ubuntu, it has limited practical value. One thing it is good for is to have a dependable, working operating system for "rescue" operations — in which case it would be prudent to ensure that partitioning and partition repair tools are installed.