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
associated 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
following 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(7) for descriptions of the following attributes:
+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | Unsafe |
+---------------+-----------------+
SEE ALSO
ioctl(2),
efi_alloc_and_init(3EXT),
dkio(4I),
attributes(7),
fmthard(8),
format(8),
prtvtoc(8)BUGS
The
write_vtoc() function cannot write a
VTOC on an unlabeled disk.
Use
format(8) for this purpose.
October 7, 2008 READ_VTOC(3EXT)
