cmdk(7D)

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 mag-
     netic removable disks.

     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 there-
     fore   considerably  more  efficient  when  many  bytes  are
     transmitted.  The  names  of  the  block  files are found in
     /dev/dsk; the names of the raw files 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.

     Fdisk partition 0 is to access the entire disk and  is  gen-
     erally used by the fdisk(1M) program.

FILES

     /dev/dsk/c ndn[ s|p]n
           block device (IDE)

     /dev/rdsk/cn dn[s|p] n
           raw device (IDE)

           where:

           cn    controller n

           dn    lun n (0-7)

           sn    UNIX system slice n (0-15)

           pn    fdisk partition (0)

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Architecture                | x86                         |
    |_____________________________|_____________________________|

SEE ALSO

     fdisk(1M),   mount(1M),   lseek(2),    read(2),    write(2),
     readdir(3C), scsi(4), vfstab(4), attributes(5), dkio(7I)