@andy-king said in Fedora 21 version 1.2 to 1.5.4 version update fails:

I would like to oput the large image files on an iscsi device do you think that is possible?

Sure, mount that iSCSI device on your FOG server, move the existing directory structure in /images to the mounted iSCSI device (unmount the old disk/partition in case it was seperate), remount the iSCSI under /images and off you go without much headache.