[otrs] Backup.PL

Hello, I'm trying to run a backup of OTRS using the backup.pl script, but is bombing out with the error below. Any help would be greatly appreciated. Thank you in advance! Can't exec "which": No such file or directory at ./backup.pl line 123, <PRODUCT> line 4. readline() on closed filehandle IN at ./backup.pl line 124. ERROR: Can't locate cp! I am running OTRS 2.2.4. The backup.pl script version is: # scripts/backup.pl - the backup script # Copyright (C) 2001-2007 OTRS GmbH, http://otrs.org/ # -- # $Id: backup.pl,v 1.9.2.1 2007/10/24 16:08:45 mh Exp $ # --