1nfsidmap(5) File Formats Manual nfsidmap(5)
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6 nfsidmap - The NFS idmapper upcall program
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9 The file /usr/sbin/nfsidmap is used by the NFS idmapper to translate
10 user and group ids into names, and to translate user and group names
11 into ids. Idmapper uses request-key to perform the upcall and cache the
12 result. /usr/sbin/nfsidmap should only be called by request-key, and
13 will perform the translation and initialize a key with the resulting
14 information.
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16 NFS_USE_NEW_IDMAPPER must be selected when configuring the kernel to
17 use this feature.
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20 The file /etc/request-key.conf will need to be modified so
21 /sbin/request-key can properly direct the upcall. The following line
22 should be added before a call to keyctl negate:
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24 create nfs_idmap * * /usr/sbin/nfsidmap %k %d 600
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26 This will direct all nfs_idmap requests to the program
27 /usr/sbin/nfsidmap The last parameter, 600, defines how many seconds
28 into the future the key will expire. This is an optional parameter for
29 /usr/sbin/nfsidmap and will default to 600 seconds when not specified.
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31 The idmapper system uses four key descriptions:
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33 uid: Find the UID for the given user
34 gid: Find the GID for the given group
35 user: Find the user name for the given UID
36 group: Find the group name for the given GID
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38 You can choose to handle any of these individually, rather than using
39 the generic upcall program. If you would like to use your own program
40 for a uid lookup then you would edit your request-key.conf so it looks
41 similar to this:
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43 create nfs_idmap uid:* * /some/other/program %k %d 600
44 create nfs_idmap * * /usr/sbin/nfsidmap %k %d 600
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46 Notice that the new line was added above the line for the generic pro‐
47 gram. request-key will find the first matching line and run the corre‐
48 sponding program. In this case, /some/other/program will handle all
49 uid lookups, and /usr/sbin/nfsidmap will handle gid, user, and group
50 lookups.
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53 Bryan Schumaker, <bjschuma@netapp.com>
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57 1 October 2010 nfsidmap(5)