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mount.nfs: Unknown error 521

Trying to mount the shared directory from the computer onto itself:

Code:

> mount 192.168.0.1:/etc /ttt -t nfs -v

mount.nfs: timeout set for Fri Jun 19 13:11:02 2009

mount.nfs: text-based options: 'addr=192.168.0.1'

mount.nfs: Unknown error 521

Is self-mount prohibited?

Quote:

Originally Posted by Dims (Post 3579829)

Is self-mount prohibited?

The Bible probably says so and it's rumoured to cause stunted growth and blindness!

Nah, don't do that

Quote:

Originally Posted by Dims (Post 3579829)

Is self-mount prohibited?

It is extremely unwise due to the memory model on most systems. If the system needs to free RAM, one thing it might do is attempt to free RAM being used by the NFS client filesystem as a buffer cache. Part of that process will be to flush changes to disk (ie over NFS to the same system), which in turn may require more RAM on the server side of the interaction. Oops, deadlock, or maybe the OOM killer will shoot down some process you prefer it didn't.

Of course, this is a generalization, YMMV, and in particular if you can stay away from OOM or near OOM conditions, or if you can ensure your NFS server stack never needs more RAM you could be golden. But who needs that stress, just don't do it!

What?

The thread is almost 13 years old and is similar to a bug report showing this was a kernel error maybe due to a bad export file and has been fixed. I've always tested nfs and cifs shares by mounting them to the server itself and never had any memory problems.