/etc/exports
QNX SDP8.0Utilities ReferenceUtilities
Define remote mountpoints for NFS mount requests
Name:
/etc/exports
/etc/exports.hostname
Description:
The exports file defines remote mountpoints for the NFS mount protocol according to the NFS server specification; see RFC 1094 (Network File System Protocol Specification) and RFC 1813 (NFS Version 3 Protocol Specification).
Note:
There isn't a default version of this file; you can create your own if you need it.
Each line in the file specifies one remote mountpoint. The first field contains the mountpoint directory path, followed optionally by a list of options and/or a list of specific hosts separated by whitespace. If no specific hosts are specified, the mountpoint is exported to all hosts.
Here are the export options:
- -mask=netmask -match=network
- Restrict access to hosts belonging to subnet defined by netmask and network.
By default, there's no restriction. Access is determined by:
((client_ip & netmask) == network)
- -norsvd
- Don't check incoming requests, they're from a reserved port. By default, NFS requests from ports greater than IPPORT_RESERVED are replied to with EACCES.
- -ro
- Export the filesystem as read-only. By default, the filesystem is exported as read/write.
- -root=uid
- Map root's uid (real user ID). By default,
root is mapped to
-2
.
Let's now look at a sample file:
/usr -root=1 rickers snowhite.cis.uoguelph.ca
/usr/local 131.104.48.16
/u -root=5 -mask=255.255.240.0 -match=131.104.0.0
/u2 -ro -mask=255.0.0.0 -match=10.0.0.0 node11 node23
The above example specifies the following:
This mountpoint: | Is exported: |
---|---|
/usr | To hosts rickers and snowhite.cis.uoguelph.ca only,
with root mapped to 1 and with read/write access.
|
/usr/local | To host 131.104.48.16 only,
with root mapped to -2 and with read/write access.
|
/u | To all hosts within 131.104.0.0 to 131.104.15.255,
with root mapped to 5 and with read/write access.
|
/u2 | To hosts node11 and node23 and to hosts belonging to
IP network 10 only, with root mapped to -2
and with read-only access.
|
Limitations:
- 1 subnet per mountpoint
- 10 hosts per mountpoint
Based on:
- RFC 1094 (Network File System Protocol Specification)
- RFC 1813 (NFS Version 3 Protocol Specification)
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