Reverse Path Name Lookup

The reverse path name lookup feature obtains the full path name of a file or directory from the inode number of that file or directory. The inode number is provided as an argument to the vxlsino administrative command, or the vxfs_inotopath application programming interface library function.

The reverse path name lookup feature can be useful for a variety of applications, such as for clients of the VxFS file change log feature, in backup and restore utilities, and for replication products. Typically, these applications store information by inode numbers because a path name for a file or directory can be very long, thus the need for an easy method of obtaining a path name.

An inode is a unique identification number for each file in a file system. An inode contains the data and metadata associated with that file, but does not include the file name to which the inode corresponds. It is therefore relatively difficult to determine the name of a file from an inode number. The ncheck command provides a mechanism for obtaining a file name from an inode identifier by scanning each directory in the file system, but this process can take a long period of time. The VxFS reverse path name lookup feature obtains path names relatively quickly.

Because of the possibility of errors with processes renaming or unlinking and creating new files, it is advisable to perform a lookup (or open) with the path name and verify that the inode number matches the path names obtained.

See the vxlsino(1M), vxfs_inotopath_gen(3) and vxfs_inotopath(3) manual pages for more information.