VERITAS File System 4.1 Administrator's Guide

File Change Log
Reverse Path Name Lookup
Chapter 8138
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.
NOTE Because symbolic links do not constitute a path to the file, the reverse path
name lookup feature cannot track symbolic links to files.
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) and vxfs_inotopath(3) online manual pages for more information.