Why to pack up database?

[iimarre]

Why do i have to pack up database when i upgrade?
Will photos disappear from database during upgrade or what?
Or is it just in case somethin goes wrong?
I don't know how to pack up so i'm trying to avoid it as long as i can.
Thanks.

[Joachim Müller]

Or is it just in case somethin goes wrong?

Exactly.

Upgrading is mandatory. Playing dead is not an option.