[R] ff package: ff objects don't reload completely on NFS drives from a different machine

Hao Cen hcen at andrew.cmu.edu
Tue Jan 26 04:20:03 CET 2010


Hi Jens,

Thanks for the suggestions. I tried closing the ff file on one nfs client
and open that file from another client. It doesn't work.

Jeff
-----Original Message-----
From: Jens Oehlschlägel [mailto:oehl_list at gmx.de] 
Sent: Monday, January 25, 2010 5:07 PM
To: hcen at andrew.cmu.edu
Cc: R-help at r-project.org
Subject: Re: [R] ff package: ff objects don't reload completely on NFS
drives from a different machine

Try to close the file on the first nfs client before reopening it on the
second nfs client. NFS has something called "close-to-open cache
consistency".
This means that two clients which have the same nfs file open, cannot rely
on seeing the updates from the respective other client. If one clients
closes, and the other client opens thereafter, it should see the changes. If
you want multiple clients to write at the same time, you should make sure
they only write non-overlapping sections (and then all need to close for
synching). Let me know if this worked for you. 
J.



More information about the R-help mailing list