Can I just download Tails on just one USB(8gb)? I only got one USB so there's that, I know that in their website they ask to use 2 sticks of Usb ( at least 4Gb ) but mine is bigger than the recommended, so why not use all of my 8Gb instead of using 2 sticks of 4?
Yes, but only under certain circumstances.
The reason it is recommending 2 USBs is that for features like encrypted persist storage and incremental updates it has to be installed from the
Tails Installer. This performs extra steps that can't be done through simply writing the .iso to the raw "block device".
You can get a working copy of Tails from just doing that but it won't give you any encrypted storage space, if that isn't part of your requirements then you do not need to use two USB sticks.
You can also install Tails through the
Tails Installer for Debian, Ubuntu or Mint, which can install directly from the existing Debian, Ubuntu or Mint installation onto a single USB stick without having to use the "Intermediary" Tails USB stick to run the installer for the intended USB stick.
There are other ways around this problem but none of them are universal (or recommended) and depend on what you have available.
So, no you won't be able to use your one 8GB as two 4GB but yes you may be able to install it with just one 8GB, if you either forgo persistence and incremental updates and just use the "Intermediary" USB installation or have a pre-existing Ubuntu, Debian or Mint install available.
Other ugly workaround ideas might be getting GRUB to boot the .iso directly, using an existing GRUB2 install to load the "Intermediary", or writing the iso to some other media and successfully getting it to boot from that to act as the point for loading the intermediary.
You can use a USB stick that is no bigger than the ISO (Tails 2.6 is a little over 1.1GiB). However, you need to have some technical ability to:
- manually partition the USB stick
- configure a bootloader capable of booting the ISO stored on the stick (i.e. GNU Grub)
- manually create the persistence volume, if you want one: it's just LUKS.
If these things mean little to you then perhaps this isn't for you. But it does work. Whether this is against recommendations is the subject of another question.
it's - generally - no problem. As it obviously is, the persistent partition IS just mounted-and-used by kernel. Regardless of the program and way of it's creation. In case of encrypted storages and so forth - unless you're using a dedicated hardware-accelerated encryption as a second USB drive that keeps the key actually "out of hands" of the OS(not just Tails), there will be no difference in even an encrypted volume case either: the hack-task of stealing the encryption key that is inside the targeted OS in any form is equal. Only 2nd USB flash with completely isolated encryption key is the different case, and - yes - in that case you better use two USB drives.