PowerScale OneFS Web Administration Guide

UNIX permissions

In a UNIX environment, file and directory access is controlled by POSIX mode bits, which grant read, write, or execute permissions to the owning user, the owning group, and everyone else.

OneFS supports the standard UNIX tools for viewing and changing permissions, ls, chmod, and chown. For more information, run the man ls, man chmod, and man chown commands.

All files contain 16 permission bits, which provide information about the file or directory type and the permissions. The lower 9 bits are grouped as three 3-bit sets, called triples, which contain the read, write, and execute (rwx) permissions for each class of users—owner, group, and other. You can set permissions flags to grant permissions to each of these classes.

Unless the user is root, OneFS checks the class to determine whether to grant or deny access to the file. The classes are not cumulative: The first class matched is applied. It is therefore common to grant permissions in decreasing order.