NFS Causing Problems?

[David Teh]

Hi folks,

On my UAT server (Solaris), there is an NFS mount (hard link) that the UAT server has with a foreign server (Windows) that is outside the WAN.

It seems to cause the host server to hang and also threads to disconnect. After removing that NFS mount, the host server didn’t hang again.

Any ideas why this happens?

Would soft link be better?

Topic

[David Harrison]

I had problems with Windows connections using the NFS server supplied by Microsoft. I installed Allegro from <a href="http://nfsforwindows.com/home&#8221; class=”bbcode_url”>http://nfsforwindows.com/home and the problem disappeared.

[James Wang]

Mounting NFS (hard mount) via WAN connection is not advised.

different between soft and hard mount

a) Hard mounts

Advantages: If the connection is lost and it is a minor problem, and you are ok with having all your NFS clients have frozen applications, and possibly have their entire systems frozen and useless until the NFS server comes back online, you may not lose any data when the NFS share becomes available again.

Disadvantages: If an application freezes and you can’t bring up the NFS server, your only option appears to be to kill that application, even if it could have easily survived write errors. Also, a simple NFS share where you dump files once in a while, and that is completely unnecessary for the system to function, can freeze the entire system indefinitely if the server loses connection to the client.

b) Soft mounts

Advantages: They work as expected (for the most part) – if the server fails, the application gets an I/O error, and keeps going.

Disadvantage: According to the nfs man page, and every other source on the internet, this leads to silent data corruption because applications get told prematurely that a write was successful when in fact the data is still in cache, unable to be written to the NFS server that we just lost connection to.

[Author]

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