From the exports(5) man page, in the "User ID Mapping" section, it says:
User ID Mapping
Very often, it is not desirable that the root user on a client machine is also treated as root when accessing files on the NFS server. To this end, uid 0 is normally mapped to a different id: the so-called anonymous or
nobodyuid. This mode of operation (called `root squashing') is the default, and can be turned off with
Here's the complete list of mapping options:
- Map requests from uid/gid 0 to the anonymous uid/gid. Note that this does not apply to any other uids or gids that might be equally sensitive, such as user
- Turn off root squashing. This option is mainly useful for diskless clients.
- Map all uids and gids to the anonymous user. Useful for NFS-exported public FTP directories, news spool directories, etc. The opposite option is
no_all_squash, which is the default setting.
I summarized the UID mapping options in the following table (assumed
1000 to be the UID of a non-privileged user, and
65534 to be the anonymous UID):
|Option||Client UID||Server UID|
- Is my summary for the
no_all_squashoption correct? If yes, when will it be useful?
- Which option is the default? The paragraph above says
no_all_squashclaims itself default in the options explanation.
Thank you in advance!