[Discuss] nfs hard links

[gaf at blu.org (Jerry Feldman)]

On 01/30/2013 09:31 AM, Edward Ned Harvey (blu) wrote:
> I don't happen to have any NFS systems handy right now to test on.
>
> When I google around, everybody's answering the wrong question - I know you can't hard link local filesystem to a remote filesystem.  I want to know remote to remote.
>
> mount mynfs:/someexport /home/someexport
> cd /home/someexport
> touch foo
> ln foo bar
>
> Can you hard link a NFS mounted file to another NFS mounted file on the same NFS system?
>
Some of this has been answered by Richard and Charles.
1. You can hard link if the exporting system supports hard links (eg is
a Unix or Linux system). I'm not sure if a Windows system that exports
NFS will support hard links
2. You can hard link only within same mount point:
So in your example, there should be no problem, but in this case
someexport and anotherexport are on the same physical file system on the
server, but are exported separately.
mount mynfs:/someexport /home/someexport
mount mynfs:/anotherexport /home/anotherexport
cd /home/someexport
touch foo
cd ../anotherexport
ln ../someexport/foo foo    ## This will fail: Invalid cross-device link

Mounted file systems essentially each have their own inode tables.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
PGP key id:3BC1EB90 
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Invalid cross-device link