Thank you everybody ! I have been damned stupid, or tired - or both ! Actually, the file was hidden behind a mount point which failed briefly, but long enough so that a backup took place - and was dumped onto the filesystem - then the mount resumed, and hid the 10 GB backup !!! Thanks again ! --- Robert GRASSO – System engineer CEDRAT S.A. 15 Chemin de Malacher - Inovallée - 38246 MEYLAN cedex - FRANCE Phone: +33 (0)4 76 90 50 45 - Fax: +33 (0)4 56 38 08 30 mailto:robert.grasso at cedrat.com - http://www.cedrat.com > -----Message d'origine----- > De : centos-bounces at centos.org > [mailto:centos-bounces at centos.org] De la part de Peter Kjellstrom > Envoyé : 1 février 2010 17:03 > À : centos at centos.org > Objet : Re: [CentOS]very large difference between df and du > (10 GB, hard to believe ) > > Indeed. At this point I'd start looking at things hiding > under mount points.