PSA: Ensure sufficient space before performing an upgrade/install

[confuzeduser]

Recently I wanted to upgrade my Sansa Fuze (v1) from Rockbox 3.8 to 3.9.  I tried the Linux installer; it quit unexpectedly after starting the install process.  So I tried again in Windows, and it kept stopping with the message "Could not write firmware" (or something to that effect).

The problem was simply that I was being a dummy.  There was only 12.8 MB free on the Fuze's root filesystem.  So I freed up 100 MB and the installer worked after that.

True story.