Overlap Partition Checking

The enhancements related to Overlap Partition Checking are described next.

Partition Overlap Checks Added to Utilities

Partion overlap checks were added to a number of commands in Digital UNIX Version 4.0. Some of the commands which use these checks are: newfs, fsck, mount, mkfdnm, swapon, voldisksetup, and voldisk. The enhanced checks require a disk label to be installed on the disk. Refer to the disklabel(8) reference page for further information.

The checks ensure that if a partition or an overlapping partition is already in use (for example, mounted or used as a swap device), the partition will not be overwritten. Additionally, the checks ensure that partitions will not be overwritten if the specific partition or an overlapping partition is marked in use in the fstype field on the disk label.

If a partition or an overlapping partition has an in-use fstype field in the disklabel, some commands inquire interactively if a partition can be overwritten.

Library Functions for Partition Overlap Checking

Two new functions, check_usage(3) and set_usage(3) are available for use by applications. These functions check whether a disk partition is marked for use and set the fstype of the partition in the disk label. See the appropriate reference pages for these functions for more information.