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(1M) program.

Files

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

block device (IDE)

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

raw device (IDE)

where:

cn

controller n.

dn

lun n (0-1).

sn

UNIX system slice n (0-15).

pn

fdisk partition (0–36).

/kernel/drv/amd64/cmdk

64-bit kernel module.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

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