cmdk@target, lun : [ partition | slice ]

The cmdk device driver is a common interface to various disk devices. The driver supports magnetic fixed disks and magnetic removable disks.

The cmdk device driver supports three different disk labels: fdisk partition table, Solaris x86 VTOC and EFI/GPT.

The block-files access the disk using the system's normal buffering mechanism and are read and written without regard to physical disk records. There is also a "raw" interface that provides for direct transmission between the disk and the user's read or write buffer. A single read or write call usually results in one I/O operation; raw I/O is therefore considerably more efficient when many bytes are transmitted. The names of the block files are found in /dev/dsk. Raw file names are found in /dev/rdsk.

I/O requests to the magnetic disk must have an offset and transfer length that is a multiple of 512 bytes or the driver returns an EINVAL error.

Slice 0 is normally used for the root file system on a disk, slice 1 as a paging area (for example, swap), and slice 2 for backing up the entire fdisk partition for Solaris software. Other slices may be used for usr file systems or system reserved area.

The fdisk partition 0 is to access the entire disk and is generally used by the fdisk(8) program.

See attributes(7) for descriptions of the following attributes:

lseek (2), read (2), write (2), readdir (3C), dkio (4I), scsi (5), vfstab (5), attributes (7), fdisk (8), mount (8)