/dev/hda [default] /dev/hdb /dev/sda /dev/sdb /dev/sdc /dev/sdd In order to write the partition table cfdisk needs something called the `geometry' of the disk: the number of `heads' and the number of `sectors per track'. Linux does not use any geometry, so if the disk will not be accessed by other operating systems, you can safely accept the defaults that cfdisk chooses for you. The geometry used by cfdisk is found as follows. First the partition table is examined, to see what geometry was used by the previous program that changed it. If the partition table is empty, or contains garbage, or does not point at a consistent geometry, the kernel is asked for advice. If nothing works 255 heads and 63 sectors/track is assumed. The geometry can be overridden on the command line or by use of the `g' command. When partitioning an empty large modern disk, picking 255 heads and 63 sectors/track is always a good idea. There is no need to set the number of cylinders, since cfdisk knows the disk size. Next, cfdisk tries to read the current partition table from the disk drive. If it is unable to figure out the partition table, an error is displayed and the program will exit. This might also be caused by incorrect geometry information, and can be overridden on the command line. Another way around this problem is with the -z option. This will ignore the partition table on the disk. The main display is composed of four sections, from top to bottom: the header, the partitions, the command line and a warning line. The header contains the program name and version number followed by the disk drive and its geometry. The partitions section always displays the current partition table. The command line is the place where commands and text are entered. The available commands are usually displayed in brackets. The warning line is usually empty except when there is important information to be displayed. The current partition is highlighted with reverse video (or an arrow if the -a option is given). All partition specific commands apply to the current partition. The format of the partition table in the partitions section is, from left to right: Name, Flags, Partition Type, Filesystem Type and Size. The name is the partition device name. The flags can be R Boot , which designates a bootable partition or R NC , which stands for "Not Compatible with DOS or OS/2". DOS, OS/2 and possibly other operating systems require the first sector of the first partition on the disk and all logical partitions to begin on the second head. This wastes the second through the last sector of the first track of the first head (the first sector is taken by the partition table itself). cfdisk allows you to recover these "lost" sectors with the maximize command (m). Note: fdisk(8) and some early versions of DOS create all partitions with the number of sectors already maximized. For more information, see the maximize command below. The partition type can be one of R Primary or Logical . For unallocated space on the drive, the partition type can also be R Pri/Log , or empty (if the space is unusable). The filesystem type section displays the name of the filesystem used on the partition, if known. If it is unknown, then Unknown and the hex value of the filesystem type are displayed. A special case occurs when there are sections of the disk drive that cannot be used (because all of the primary partitions are used). When this is detected, the filesystem type is displayed as R Unusable . The size field displays the size of the partition in megabytes (by default). It can also display the size in sectors and cylinders (see the change units command below). If an asterisk (*) appears after the size, this means that the partition is not aligned on cylinder boundaries.