What is written to hard drive with thumb drive install or live cd

[murof]

I am pretty new to Linux so please forgive me if this is a stupid question. I would like to run Fedora on a thumb drive and be able to save my settings/installed applications etc all to the thumb drive. I found an app 'unetbootin' - that seems to help with this. Anyhow, I am wondering if I run Fedora from a thumb drive, does it write any files to the internal hard drive on the computer or is everything automatically run/saved to the thumb drive? Also, if I run a liveCD does it save everything in RAM for that session and then delete it when I reboot or is that written somewhere also? Thank you very much.

[Dangermouse]

I think this is what you are looking for
https://fedorahosted.org/liveusb-creator/

[murof]

Yes, I am wondering if anything is written to the hard drive of the computer you run the USB OS on or if everything is automatically written to the usb stick and the hard drive stays protected. Thank you.

[sideways]

nothing is wriiten to the hard disk

in fedora you can specify a persistent home and a general persistence layer on the usb disk, see options for livecd-iso-to-disk.

General persistence layer is unstable, especially if you do a large update, best to have a persistent home directory and use scripts and yumdownloader to store packages required in future boots

[murof]

If you don't mind me asking, is Persistant Home an option on the livecd-iso-to-disk? Thanks again.

[sideways]

Originally Posted by murof

If you don't mind me asking, is Persistant Home an option on the livecd-iso-to-disk? Thanks again.

Yes, --home-size-mb, I also use --unencrypted-home since it seems more reliable, but I don't have sensitive data stored either.

[root@localhost ~]# livecd-iso-to-disk
/usr/bin/livecd-iso-to-disk [--reset-mbr] [--noverify] [--overlay-size-mb <size>] [--home-size-mb <size>] [--unencrypted-home] <isopath> <usbstick device>