Hi We use CentOS and RHEL, the 5.5 RHEL ISO for x86_64 is 3.7GB (**), the CentOS one is 4602MB (***) split over two DVDs. Is this reasonable and correct? Any ideas why would there be such a discrepancy if they are built from the same (or very similar) source? Regards Anthony Caetano ** the md5sum checks out, and RHN lists the size as 3,532 MB *** CentOS-5.5-x86_64-bin-DVD-1of2.iso + CentOS-5.5-x86_64-bin-DVD-2of2.iso (according to ftp.heanet.ie:/pub/centos/5.5/isos/x86_64 )