http://www.walkernews.net/2008/07/06/how-to-create-iso-image-of-directory-or-filesystem-in-linux/ For example, to dump the content of /home/user directory into a standard CD ISO-9660 filesystem image with file name called DB2Wkg.iso:
mkisofs -o user.iso /home/user
To create CD ISO image of directories that contain long file name or non-8.3 format (particularly if you want to burn the CD image for use in Windows system), use the -J option switch that generates Joliet directory records in addition to regular iso9660 file names. For example, to create CD image of Vista SP1 directory:
mkisofs -o VitaSP1.iso -J /home/user/downlaods/VistaSP1
dd stands for disk dump, if stands for input file, of stands for output file
Used to make images of a device, like a cdrom
dd if=/dev/cdrom of=/home/user/files/vista.iso
mkdir /mnt/VistaSP1 mount -o loop /home/user/downloads/VistaSP1 /mnt/VistaSP1
