NFS: Update idmapper documentation

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Bryan Schumaker 2012-01-26 16:54:25 -05:00 committed by Trond Myklebust
parent 3cd0f37a2c
commit a602bea3e7

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@ -4,13 +4,21 @@ ID Mapper
=========
Id mapper is used by NFS to translate user and group ids into names, and to
translate user and group names into ids. Part of this translation involves
performing an upcall to userspace to request the information. Id mapper will
user request-key to perform this upcall and cache the result. The program
/usr/sbin/nfs.idmap should be called by request-key, and will perform the
translation and initialize a key with the resulting information.
performing an upcall to userspace to request the information. There are two
ways NFS could obtain this information: placing a call to /sbin/request-key
or by placing a call to the rpc.idmap daemon.
NFS will attempt to call /sbin/request-key first. If this succeeds, the
result will be cached using the generic request-key cache. This call should
only fail if /etc/request-key.conf is not configured for the id_resolver key
type, see the "Configuring" section below if you wish to use the request-key
method.
If the call to /sbin/request-key fails (if /etc/request-key.conf is not
configured with the id_resolver key type), then the idmapper will ask the
legacy rpc.idmap daemon for the id mapping. This result will be stored
in a custom NFS idmap cache.
NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to use this
feature.
===========
Configuring