Insufficient disk space when restoring a small backup

sql-server, sql-server-2005

Solution

Probably because the backup is compressed, or because there is a very large log file that doesn't need to be part of the backup itself, or because the data file itself has been cleaned out - the backup is only comprised of pages that contain data. But when restored, it still has to expand the data file to its original size, even if most of it is empty.

Show us what the size column says when you run:

RESTORE FILELISTONLY FROM DISK = '[path]\whatever.bak';

Problem

I'm trying to restore a database from 32MB backup. I have 6GB available on my disk. When I'm trying to restore the backup it shows the insufficient disk space error. How is it possible that a 32MB backup requires more than 6GB of disk space?

Original source