The law states, (in abridged form here)
It is not an infringement of copyright for a person who owns a copy of a work toRead the full text here, starting at page 57
reproduce the source copy solely for backup purposes in case the source copy is lost, damaged or otherwise rendered and unusable. The source copy must not be an infringing copy and any technological protection measures (digital locks) on the copy must not be circumvented to make the copy. The back-up copy is not to be given away and must be destroyed immediately after the person ceases to own or have licence to use the source copy. The backup copy becomes source copy if the source copy is lost, damaged or otherwise rendered unusable.
As I understand it, it's OK to make a back up copy, but the original is the one that circulates and the back up sits in storage.
A separate section of the Act deals with backup copies of computer programs and is somewhat more restrictive.
(I'm not a lawyer. See Proverbs 12:15b )