Chapter 2. Configuration
To add an NFS share, click the Add button. The
dialog box shown in Figure 2-1 will appear.
The Basic tab requires the following information:
Directory — Specify the directory to
share, such as /tmp.
Host(s) — Specify the host(s) to
which to share the directory. Refer to Chapter 3 Hostname Formats for an explanation of possible
formats.
Basic permissions — Specify whether
the directory should have read-only or read/write permissions.
The General Options tab allows the following
options to be configured:
Allow connections from port 1024 and higher
— Services started on port numbers less than 1024 must be
started as root. Select this option to allow the NFS service to be
started by a user other than root. This option corresponds to
insecure.
Allow insecure file locking — Do not
require a lock request. This option corresponds to
insecure_locks.
Disable subtree checking — If a
subdirectory of a file system is exported, but the entire file
system is not exported, the server checks to see if the requested
file is in the subdirectory exported. This check is called
subtree checking. Select this option to
disable subtree checking. If the entire file system is exported,
selecting to disable subtree checking can increase the transfer
rate. This option corresponds to
no_subtree_check.
Sync write operations on request —
Enabled by default, this option does not allow the server to reply
to requests before the changes made by the request are written to
the disk. This option corresponds to sync. If
this is not selected, the async option is
used.
The User Access tab allows the following options to
be configured:
Treat remote root user as local root
— By default, the user and group IDs of the root user are both
0. Root squashing maps the user ID 0 and the group ID 0 to the user
and group IDs of anonymous so that root on the client does not have
root privileges on the NFS server. If this option is selected, root
is not mapped to anonymous, and root on a client has root
privileges to exported directories. Selecting this option can
greatly decrease the security of the system. Do not select it unless
it is absolutely necessary. This option corresponds to
no_root_squash.
Treat all client users as anonymous users
— If this option is selected, all user and group IDs are
mapped to the anonymous user. This option corresponds to
all_squash.
Specify local user ID for anonymous
users — If Treat all client users
as anonymous users is selected, this option lets
you specify a user ID for the anonymous user. This option
corresponds to anonuid.
Specify local group ID for anonymous
users — If Treat all client users as
anonymous users is selected, this option lets you
specify a group ID for the anonymous user. This option corresponds
to anongid.
To edit an existing NFS share, select the share from the list, and click
the Properties button. To delete an existing NFS
share, select the share from the list, and click the
Delete button.
After clicking OK to add, edit, or delete an NFS
share from the list, the changes take place immediately — the
server daemon is restarted, and the old configuration file is saved as
/etc/exports.bak. The new configuration is written
to /etc/exports.
The NFS Server Configuration Tool reads and writes directly to
the /etc/exports configuration file. Thus, the file
can be modified manually after using the tool, and the tool can be used
after modifying the file manually (provided the file was modified with
correct syntax).
