Where does free space from my ubuntu livecd come from?

<p>i can save files to disk, but it's a livecd that i can't write to. i still have 900 MB of free space that i can write to. but linux can't write anything to my ntfs hard drive nor do i have any other drives attached to it. might it possibly be in RAM? my computer has 2 GB of RAM.</p>

<p>900 MB sounds like the size of your CD. However, I'm pretty sure when using the livecd, any information you save "to disk" is effectively lost if you don't install Ubuntu that session. The couple of times I've used my livecd (to reformat my drive, etc.) it wasn't using my hard drive at all (hence, you can reformat your hard drive), which means it ran a lot slower than it usually does, because it was using the CD as a hard drive (for accessing files) and the RAM as memory (to run programs, save preferences, etc... which was what RAM is usually, but more stuff had to be on RAM because Ubuntu couldn't install anything onto the drive).</p>

<p>You'd probably get better answers on an Ubuntu forum, though.</p>

<p>You're right! It is your RAM. :)</p>

<p>Ubuntu's CD contain compressed apps which are extracted to a RAMdisk on-the-fly upon bootup. In a sense, it's a combination of both you RAM and CD.</p>

<p>So, any changes you make are noted in your RAM, whereas anything that was there is decompresed from the CD as necessary. When you reboot, any changes you make will disappear because the actual CD is read-only, and RAM clears itself upon powerdown.</p>

<p>That last paragraph is not true. There are ways for the stuff in RAM to stay there until next boot. One way is to keep your RAM extremely cool. this can keep the data there for a few seconds. This is touched upon on wikipedia's article Cold</a> boot attack - Wikipedia, the free encyclopedia. After reading this you shall be enlightened on how you can keep the data.</p>