read_vtoc(3EXT) 					    Extended Library Functions						   read_vtoc(3EXT)

NAME

       read_vtoc, write_vtoc - read and write a disk's VTOC

SYNOPSIS

       cc [ flag ... ] file ... -ladm [ library ... ]
       #include <sys/vtoc.h>

       int read_vtoc(int fd, struct vtoc *vtoc);

       int write_vtoc(int fd, struct vtoc *vtoc);

       int read_extvtoc(int fd, struct extvtoc *extvtoc);

       int write_extvtoc(int fd, struct extvtoc *extvtoc);

DESCRIPTION

       The  read_vtoc()  and read_extvtoc() functions return the VTOC (volume  table  of contents)  structure  that is stored on  the disk associ-
       ated with the open file descriptor fd. On disks larger than 1 TB read_extvtoc() must be used.

       The write_vtoc() and write_extvtoc() function stores the VTOC structure on the disk associated with the open file descriptor fd.  On  disks
       larger then 1TB write_extvtoc() function must be used.

       The fd argument refers to any slice on a raw disk.

RETURN VALUES

       Upon  successful  completion,  read_vtoc() and read_extvtoc() return a positive integer indicating the slice index associated with the open
       file descriptor. Otherwise, they return a negative integer indicating one of the following errors:

       VT_EIO	      An I/O error occurred.

       VT_ENOTSUP     This operation is not supported on this disk.

       VT_ERROR       An unknown error occurred.

       VT_OVERFLOW    The caller attempted an operation that is illegal on the disk and may overflow the fields in the data structure.

       Upon successful completion, write_vtoc() and write_extvtoc() return 0. Otherwise, they return a negative integer indicating one of the fol-
       lowing errors:

       VT_EINVAL      The VTOC contains an incorrect field.

       VT_EIO	      An I/O error occurred.

       VT_ENOTSUP     This operation is not supported on this disk.

       VT_ERROR       An unknown error occurred.

       VT_OVERFLOW    The caller attempted an operation that is illegal on the disk and may overflow the fields in the data structure.

ATTRIBUTES

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

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       fmthard(1M), format(1M), prtvtoc(1M), ioctl(2), efi_alloc_and_init(3EXT), attributes(5), dkio(7I)

BUGS

       The write_vtoc() function cannot write a  VTOC on an unlabeled disk. Use format(1M) for this purpose.

SunOS 5.11							    7 Oct 2008							   read_vtoc(3EXT)