Provided by: openafs-client_1.8.13.2-1ubuntu1_amd64 
NAME
fs_exportafs - Configures export of AFS to clients of other file systems
SYNOPSIS
fs exportafs -type <exporter name>
[-start <start/stop translator (on | off)>]
[-convert <convert from afs to unix mode (on | off)>]
[-uidcheck <run on strict 'uid check' mode (on | off)>]
[-submounts <allow nfs mounts to subdirs of /afs/.. (on | off)>]
[-clipags <use client-assigned PAGs (on | off)>]
[-pagcb <callback clients to get creds (on | off)>]
[-help]
fs exp -t <exporter name>
[-st <start/stop translator (on | off)>]
[-co <convert from afs to unix mode (on | off)>]
[-u <run on strict 'uid check' mode (on | off)>]
[-su <allow nfs mounts to subdirs of /afs/.. (on | off)>]
[-cl <use client-assigned PAGs (on | off)>]
[-p <callback clients to get creds (on | off)>]
[-h]
DESCRIPTION
The fs exportafs command sets (if the -start argument is provided) or reports (if it is omitted) whether
the machine can reexport the AFS filespace to clients of a non-AFS file system. To control certain
features of the translation protocol, use the following arguments:
• To control whether the UNIX group and other mode bits on an AFS file or directory are set to match
the owner mode bits when it is exported to the non-AFS file system, use the -convert argument.
• To control whether tokens can be placed in a credential structure identified by a UID that differs
from the local UID of the entity that is placing the tokens in the structure, use the -uidcheck
argument. The most common use is to control whether issuers of the knfs command can specify a value
for its -id argument that does not match their local UID on the NFS/AFS translator machine.
• To control whether users can create mounts in the non-AFS filespace to an AFS directory other than
/afs, use the -submounts argument.
OPTIONS
-type <exporter name>
Names the alternate file system to which to reexport the AFS filespace. The only acceptable value is
"nfs", in lowercase letters only.
-start <on | off>
Enables the local machine to reexport the AFS filespace if the value is "on", or disables it if the
value is "off". Omit this argument to report the current setting for all of the configurable
parameters.
-convert <on | off>
Controls the setting of the UNIX group and other mode bits on AFS files and directories exported to
the non-AFS file system. If the value is "on", they are set to match the owner mode bits. If the
value is "off", the bits are not changed. If this argument is omitted, the default value is "on".
-uidcheck <on | off>
Controls whether tokens can be placed in a credential structure identified by a UID that differs from
the local UID of the entity that is placing the tokens in the structure.
• If the value is on, the UID that identifies the credential structure must match the local UID.
With respect to the knfs command, this value means that the value of -id argument must match the
issuer's local UID on the translator machine. In practice, this setting makes it pointless to
include the -id argument to the knfs command, because the only acceptable value (the issuer's
local UID) is already used when the -id argument is omitted.
Enabling UID checking also makes it impossible to issue the klog and pagsh commands on a client
machine of the non-AFS file system even though it is a system type supported by AFS. For an
explanation, see klog(1).
• If the value is off (the default), tokens can be assigned to a local UID in the non-AFS file
system that does not match the local UID of the entity assigning the tokens.
With respect to the knfs command, it means that the issuer can use the -id argument to assign
tokens to a local UID on the NFS client machine that does not match his or her local UID on the
translator machine. (An example is assigning tokens to the MFS client machine's local superuser
"root".) This setting allows more than one issuer of the knfs command to make tokens available to
the same user on the NFS client machine. Each time a different user issues the knfs command with
the same value for the -id argument, that user's tokens overwrite the existing ones. This can
result in unpredictable access for the user on the NFS client machine.
-submounts <on | off>
Controls whether a user of the non-AFS filesystem can mount any directory in the AFS filespace other
than the top-level /afs directory. If the value is "on", such submounts are allowed. If the value is
"off", only mounts of the /afs directory are allowed. If this argument is omitted, the default value
is "off".
-clipags <on | off>
Turning on this option enables support for "client-assigned PAGs". With client-assigned PAGs, an NFS
client can manage its own AFS pags, and inform the NFS translator machine what PAG we are using,
instead of the NFS translator machine keeping track of PAGs. An NFS client machine can do this if it
has the "afspag" kernel module loaded, which tracks PAGs but otherwise does not implement AFS
functionality, and forwards all requests to the NFS translator machine.
You should only turn on this option if you are making use of client-assigned PAGs, and you trust the
NFS client machines making use of the translator. This option is off by default.
-pagcb <on | off>
Turning on this option means that the NFS translator machine will contact new NFS clients in order to
obtain their credentials and sysnames. This option can be useful so that client credentials are not
lost if the translator machine is rebooted, or if an NFS client is "moved" to using a different
translator. This functionality will only work with NFS clients that are also running the "afspag"
kernel module.
Using this option with NFS clients not running with the "afspag" kernel module would cause long
timeouts when the translator machine attempts to contact the client to obtain its credentials and
sysname list. This option is off by default.
-help
Prints the online help for this command. All other valid options are ignored.
OUTPUT
If the machine is not even configured as a server of the non-AFS file system, the following message
appears:
Sorry, the <file_system>-exporter type is currently not supported on
this AFS client
If the machine is configured as a server of the non-AFS file system but is not currently enabled to
reexport AFS to it (because the -start argument to this command is not set to "on"), the message is as
follows:
'<file_system>' translator is disabled
If the machine is enabled to reexport AFS, the following message precedes messages that report the
settings of the other parameters.
'<file_system>' translator is enabled with the following options:
The following messages indicate that the -convert argument is set to "on" or "off" respectively:
Running in convert owner mode bits to world/other mode
Running in strict unix mode
The following messages indicate that the -uidcheck argument is set to "on" or "off" respectively:
Running in strict 'passwd sync' mode
Running in no 'passwd sync' mode
The following messages indicate that the -submounts argument is set to "on" or "off" respectively:
Allow mounts of /afs/.. subdirs
Only mounts to /afs allowed
EXAMPLES
The following example shows that the local machine can export AFS to NFS client machines.
% fs exportafs nfs
'nfs' translator is enabled with the following options:
Running in convert owner mode bits to world/other mode
Running in no 'passwd sync' mode
Only mounts to /afs allowed
The following example enables the machine as an NFS server and converts the UNIX group and other mode
bits on exported AFS directories and files to match the UNIX owner mode bits.
% fs exportafs -type nfs -start on -convert on
The following example disables the machine from reexporting AFS to NFS client machines:
% fs exportafs -type nfs -start off
PRIVILEGE REQUIRED
The issuer must be logged in as the local superuser root.
SEE ALSO
klog(1), knfs(1)
COPYRIGHT
IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
This documentation is covered by the IBM Public License Version 1.0. It was converted from HTML to POD
by software written by Chas Williams and Russ Allbery, based on work by Alf Wachsmann and Elizabeth
Cassell.
OpenAFS 2025-03-21 FS_EXPORTAFS(1)