Explaining the most basic fundamentals.
At its core, MineOS is a ramdisk-based Linux distro. That's mostly because tinycorelinux made it this way, and it is a terrific model.
By tinycorelinux (and more specifically, what I use 'microcore') being ramdisk-based, changes can be made to the main filesystem that are undone on reboot--the filesystem is as fresh as the first day it was installed. This provides tolerance for user-errors, such as...deleting files from the root / and also making sure that stagnant, worthless files don't bloat up the system a la Windows.
This is problematic though, if there are changes you are certain you want and want it to happen every time MineOS is rebooted. Or is it? Tinycorelinux provides a persistence file which will allow user-changes to be there every time you want it to be. This means you can pretty much delete anything thats not in /mnt/sda1 and it can be undone with a reboot.
These files are saved in /mnt/sda1/tce/mydata.tgz. This is a tarballed archive of all the files a user wants to keep from reboot to reboot. The current versions of each file is archived each time the user executes: 'sudo filetool.sh -b'
What files does it contain? The files it uses are the ones listed in /opt/.filetool.lst. This is a file you can feel welcome to edit at any time--it's completely safe. You can see what files are backed up with the command: 'cat /opt/.filetool.lst' -- also, you can open it up and edit it with 'vi' or 'nano'.
So, in closing. Remember, changes on a mounted hard drive /mnt/sda1 or /mnt/hda1 will ALWAYS persist from reboot to reboot no matter what. The only files that persist on the other part of your filesystem are those that are indicated in the /opt/.filetool.lst file.
Once the file has been edited, and the file is properly listed in .filetool.lst, the essential step is 'sudo filetool.sh -b'. This means 'go through the list of files in /opt/.filetool.lst and archive them up into the file mydata.tgz'