NAME

hk − RK611/RK06, RK07 moving-head disk

DESCRIPTION

The RK611/RK711 controller supports up to eight RK06/RK07 disk drives. 

Refer to the ULTRIX-11 System Management Guide, Section 1.4 for information about logical disk names and Appendix D for disk partition sizes. 

The hk files access the disk via the system’s normal buffering mechanism and may be read and written without regard to physical disk records. 

A ’raw’ interface provides for direct transmission between the disk and the user’s read or write buffer.  A single read or write call results in exactly one I/O operation and therefore raw I/O is considerably more efficient when many words are transmitted.  The names of the raw files conventionally begin with an extra ’r.’ In raw I/O the buffer must begin on a word boundary. 

FILES

/dev/hk##, /dev/rhk##

SEE ALSO

ULTRIX-11 System Management Guide, Section 2.6 and Appendix A
ULTRIX-11 Software Technical Description

RESTRICTIONS

In raw I/O read and write(2) truncate file offsets to 512-byte block boundaries, and write scribbles on the tail of incomplete blocks.  Thus, in programs that are likely to access raw devices, read, write and lseek(2) should always deal in 512-byte multiples.