NFS: folder permission inheritance

Swakoo · 06-19-2007, 05:19 AM

hi guys,

i've been playing with NFS, and I realised that if I just mount the server folder, that folder permissioning will be of what is specified in the server.

E.g. if the folder is created on the server by UID 500 (user1), when I mount on the client, the permission will belong to UID 500.

But client's UID 500 could be someone else. How can I manipulate that?

Thanks!

acid_kewpie · 06-20-2007, 01:56 PM

well you have a centralized user base in line with that really, ldap or such where a uid is persistent across an enterprise.

outside of that you can mangle uids at nfs level if you really need to... http://www.faqs.org/docs/linux_netwo...s.exports.html

Swakoo · 06-25-2007, 02:13 AM

hi there, i've looked at the link you send me... and something caught my eye:

Code:

map_identity

    This option tells the server to assume that the client uses the same uids and gids as the server. This option is on by default.
map_daemon

    This option tells the NFS server to assume that client and server do not share the same uid/gid space. rpc.nfsd then builds a list that maps IDs between client and server by querying the client's rpc.ugidd daemon.
map_static

    This option allows you to specify the name of a file that contains a static map of uids and gids. For example, map_static=/etc/nfs/vlight.map would specify the /etc/nfs/vlight.map file as a uid/gid map. The syntax of the map file is described in the exports(5) manual page.
map_nis

    This option causes the NIS server to do the uid and gid mapping.

map_daemon seems to suggest that I can use NFS and not base the permission on UID/GID only?

Also, it seems that map_static means I can create a file to specify the mapping...

are these 2 related... or separately used?

So if I don't have NIS service within my network, the only way out is to manually ensure all uid/gid are consistent throughout the network? Unless the above works?

thanks for your tip!

acid_kewpie · 06-25-2007, 02:21 AM

i've never done uid mapping there, but i guess the first way, the server asks to the client "what uid does user bob have on your system?" and then converts the files with local uid for bob to be the rmeote one over that specific connection...

again these are going to ways to get around exisiting problems. if the problem is eradicated, you'll not have any work to do in the first place.

Swakoo · 06-25-2007, 04:23 AM

Haha that's true.

I think its either a NIS solution, or I need to track all UIDs manually.

One question: Are there anyways to automate mounting of NFS drives, or do I need to enter manually the IP into the server and client?

acid_kewpie · 06-25-2007, 04:29 AM

automating? autonfs can possibly cover this, but i'm not really sure what you mean.

NIS is generally being replaced by LDAP in new installations. centralized ldap user authentication would solve a huge amount of problems you don't even know exists yet...