I Still Don't Get It - root!

[kalpana]

My root filled up again. I disconnected all my drives and started an experiment with a free SSD. Created two logical volumes, LV1 for / and LV2 for /home - plenty of physical space within the two LVs. I then started to add additional LVs - this time for virtual machines. Then my / started to fill and suddenly I was at the end of a precipice, / was full up. So .... I'm thinking I should not think of / being all the files and folders that were installed in LV1 but, because everything in Linux is under /, / is in fact everything that is loaded onto my PC. So ... the more additional LVs I create the more / fills up. To address this I have to expand LV1 to accommodate more space. To me this is odd, these extra LVs have their own space on the SSD, separate from LV1. If I add three extra LVs (with still plenty of physical space/capacity on the SSD) how does increasing the size of LV1 stop my / from filling up? I have played with different mount points but as everything is under / this doesn't really matter.