exports(4)
Requires Optional NFS Services Software
NAME
exports − NFS file systems being exported
SYNOPSIS
/etc/exports
DESCRIPTION
File /etc/exports describes the file systems that are being exported to NFS clients. The system administrator creates it using a text editor. mountd(1M) processes it each time a mount request is received.
/etc/exports contains a list of file systems and the netgroup(4) or machine names allowed to remotely mount each file system. The file system names are left-justified and followed by a list of names separated by white space. The names are searched for in /etc/netgroup then in /etc/hosts. A file system name with no accompanying name list means the file system is available to everyone.
A # anywhere in the file indicates a comment extending to the end of that line. Lines beginning with white space are continuation lines.
Options
−async Specifying −async increases write performance on the NFS server by causing asynchronous writes on the NFS server. The −async option can be specified anywhere on the command line after the file system name. Before using the option, refer to WARNINGS below.
EXAMPLES
/usrclients# export to my clients
/usr/local# export to the world
/usr2appollo zeus thor# export to only these
# machines
/usr2−async zeus# export to this machine
# and cause asynchronous
# writes on the NFS
# server
WARNINGS
Do not use the −async option if one of the following conditions applies to a file system that you want to export:
• The file system contains files that are accessed using the O_SYNCIO flag (which is set by fcntl(2) or open(2) calls),
• The file system contains data that cannot be reconstructed (for example, the file system contains database files),
• The file system contains files synchronized with fsync(2), or
• The file system contains critical applications requiring absolute data integrity.
If you are unsure whether any of the previous conditions apply, do not use the −async option.
If the −async option is used, an unreported data loss may occur if the option is set and the NFS server hardware experiences a power loss, system panic, or other failure. Specifically, blocks which have been queued for the server’s disk, but have not yet been written to the disk may be lost.
AUTHOR
exports was developed by Sun Microsystems, Inc.
FILES
/etc/exports
SEE ALSO
Hewlett-Packard Company — HP-UX Release 8.05: June 1991