NAME

cmdk - common disk driver

SYNOPSIS

cmdk@target, lun : [ partition | slice ]

DESCRIPTION

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.

FILES

/dev/dsk/cndn[s|p]n

/dev/rdsk/cndn[s|p]n

/kernel/drv/cmdk

/kernel/drv/amd64/cmdk

ATTRIBUTES

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

SEE ALSO

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