df hangs -- nfs related problem

[Todd Denniston]

Patrick O'Callaghan wrote, On 01/07/2009 10:16 AM:
> That would depend on which is worse, potentially losing data or having
> a client machine hang because the server is (perhaps temporarily)
> unavailable. It depends totally on the specific application scenario.
> To quote nfs(5):
> 
> <quote>
> A  so-called  "soft"  timeout can cause silent data corruption in
> certain cases. As such, use the soft option only when client
> responsiveness is more important than data integrity.  Using NFS over
> TCP or increasing the value of the retrans option  may  mitigate some
> of the risks of using the soft option.
> </quote>
> 
> IOW there is no "right" answer to this.
> 
> poc
> 

I agree that there is no `"right" answer to this`, but from experience I have 
found that the best answer to using NFS without data loss and without 
_permanent_ application lockup is to use:
hard,intr

'soft' on the other hand has lost me much data and caused many a bottle of 
administrator headache remedy to be used.  Now a LART is called for anytime I 
find someone on my network using soft... even if they have not yet told me 
they are having problems with NFS data loss.

-- 
Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter