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getdiskbyname_r(3) [osf1 man page]

getdiskbyname(3)					     Library Functions Manual						  getdiskbyname(3)

NAME
getdiskbyname, getdiskbyname_r - Get the disk description using a disk name LIBRARY
Standard C Library (libc) SYNOPSIS
#include <sys/disklabel.h> #include <sys/types.h> struct disklabel *getdiskbyname( char *name); int getdiskbyname_r( char *name, struct disklabel *disk, char *boot, int boot_len); PARAMETERS
Specifies a common name for the disk drive whose geometry and partition characteristics are sought. Points to the structure that will con- tain the returned disk description. Points to the buffer that will contain the optional names of the primary and secondary bootstraps. Specifies the length of boot. This should be BUFSIZ. DESCRIPTION
Operations supported by the getdiskbyname function are also supported by the createlabel function. See The getdiskbyname and getdiskby- name_r functions are supported only for backward compatibility with DIGITAL UNIX Version 4.0 and earlier versions. These functions will be retired in a future release of Tru64 UNIX. The getdiskbyname() function uses a disk (disk drive) name to return a pointer to a structure that describes the geometry and standard par- tition characteristics of the named disk drive. Information obtained from the /etc/disktab database file is written to the type disklabel structure space referenced by the returned pointer. The getdiskbyname_r() function is the reentrant version of getdiskbyname(). Upon successful completion, getdiskbyname_r() returns a value of 0 (zero); the returned structure is pointed at by disk. Upon error, it returns a value of -1, and may set errno to [EINVAL]. RETURN VALUES
Upon successful completion, the getdiskbyname() function, returns a pointer to a type disklabel structure. ERRORS
Either disk or boot is NULL, or boot_len is not equal to BUFSIZ. RELATED INFORMATION
Functions: createlabel(3) Files: disklabel(4), disktab(4) Commands: disklabel(8) delim off getdiskbyname(3)

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disklabel(4)						     Kernel Interfaces Manual						      disklabel(4)

NAME
disklabel - Disk pack label SYNOPSIS
#include <sys/disklabel.h> DESCRIPTION
Each disk or disk pack on a system may contain a disk label which provides detailed information about the geometry of the disk and the par- titions into which the disk is divided. It should be initialized when the disk is formatted, and may be changed later with the disklabel program. This information is used by the system disk driver and by the bootstrap program to determine how to program the drive and where to find the file systems on the disk partitions. Additional information is used by the file system in order to use the disk most effi- ciently and to locate important file system information. The description of each partition contains an identifier for the partition type (standard file system, swap area, etc.). The file system updates the in-core copy of the label if it contains incomplete information about the file system. The label is located in sector number LABELSECTOR of the drive, usually sector 0 (zero) where it may be found without any information about the disk geometry. It is at an offset LABELOFFSET from the beginning of the sector, to allow room for the initial bootstrap. The disk sector containing the label is normally made read-only so that it is not accidentally overwritten by pack-to-pack copies or swap opera- tions; the DIOCWLABEL ioctl, which is done as needed by the disklabel program, allows modification of the label sector. A copy of the in-core label for a disk can be obtained with the DIOCGDINFO ioctl; this works with a file descriptor for a block or charac- ter (raw) device for any partition of the disk. The in-core copy of the label is set by the DIOCSDINFO ioctl. The offset of a partition cannot generally be changed, nor made smaller while it is open. One exception is that any change is allowed if no label was found on the disk, and the driver was able to construct only a skeletal label without partition information. Finally, the DIOCWDINFO ioctl operation sets the in-core label and then updates the on-disk label; there must be an existing label on the disk for this operation to succeed. Thus, the initial label for a disk or disk pack must be installed by writing to the raw disk. All of these operations are normally done using the disklabel program. RELATED INFORMATION
Files: disktab(4) Commands: disklabel(8) delim off disklabel(4)
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