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On Monday 27 July 2009 03:18:34 Harry Putnam wrote: |
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> I'm not that familiar with nfs usage ... only used lightly a few |
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> times. |
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> |
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> I have an opensolaris nfs server serving a share to my gentoo box. |
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> |
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> The mount point is set as owner:group of my user (reader). |
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> |
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> Also has the set-gid bit set. |
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> |
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> ls -ld /projects |
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> drwxr-sr-x 2 reader wheel 48 Jun 24 07:08 /projects |
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> |
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> And the mount settings in /etc/fstab |
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> (zfs is the hostname of the opensolaris server) |
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> |
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> zfs:/projects /projects nfs noauto,users,exec,dev 0 0 |
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> |
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> With those settings my user or root can mount it. |
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> |
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> When its mounted the permissions change to this: |
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> |
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> ls -ld /projects |
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> drwxr-sr-x+ 13 reader man 14 Jul 25 09:47 /projects |
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> |
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> Whats with the `man' group? |
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|
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The way nfs works is that it takes a remote filesystem and *mounts* it |
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locally, exactly as if it were a local filesystem. It is not a share. The |
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inodes are exported over nfs and that directory is owned by a group with gid |
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of say X. On your local machine that gid just happens to be the man group. |
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|
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There is nothing much you can do about this except: |
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|
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Renumber your gid's locally to match the nfs server, |
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or renumber the nfs share gids to match your local machine |
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|
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> Also, when mounted I find when I try to copy somethihng with the -a |
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> option, which tries to maintain any permission settings. It causes an |
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> error warning... (although the copy is done). |
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> |
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> cp -a file file1 |
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> cp: preserving permissions for `file1': Operation not supported |
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|
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Full paths please. I can't see which way the copy is going. |
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|
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I suspect that your user on the nfs server is not a member of the group that |
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has the same gid as your local man group. |
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> |
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> And the files permissions end up: |
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> ls -l file* |
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> -rw-r--r--+ 1 reader man 223962 Jul 26 15:56 file |
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> -rw-r--r--+ 1 reader reader 223962 Jul 26 15:56 file1 |
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> |
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> Is there some way to set it up so that permissions can be copied? |
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> Also to alow the set-gid setting to work? |
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|
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Golden rule with nfs: |
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|
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It was designed for the case of a diskless client mounts it's home or root |
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directories over the network, while exporting passwd and shadow files over |
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NIS. That is evident in it's design and there is no facility to change uids |
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and gids on the fly. You do not authenticate with nfs, the server assumes that |
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the request coming from the client is OK and treats it exactly as it would a |
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request from a local user on a local disk. This is the primary reason why nfs |
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performs so well. |
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|
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It is up to you to make sure your uids and gids everywhere match and work. nfs |
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cannot and will not help with this. |
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|
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-- |
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alan dot mckinnon at gmail dot com |