Under linux/unix, if you remove a file that a currently running process still
has open, the file isn't really removed. Once the process closes the file, the
OS then removes the file handle and frees up the disk blocks. This process is
complicated slightly when the file that is open and removed is on an NFS mounted
filesystem. Since the process that has the file open is running on one machine
(such as a workstation in your office or lab) and the files are on the file
server, there has to be some way for the two machines to communicate information
about this file. The way NFS does this is with the .nfsNNNN files. If you try to
remove one of these file, and the file is still open, it will just reappear with
a different number. So, in order to remove the file completely you must kill the
process that has it open.
If you want to know what process has this file open, you can use 'lsof .nfs1234'. Note, however, this will only work on the machine where the processes that has the file open is running. So, if your process is running on one machine (eg. bobac) and you run the lsof on some other burrow machine (eg. silo or prairiedog), you won't see anything.
Example
% lsof .nfsC23D
Unix: lsof: Command not found
Instead try
/usr/sbin/lsof .nfsC23D
If you want to know what process has this file open, you can use 'lsof .nfs1234'. Note, however, this will only work on the machine where the processes that has the file open is running. So, if your process is running on one machine (eg. bobac) and you run the lsof on some other burrow machine (eg. silo or prairiedog), you won't see anything.
Example
% lsof .nfsC23D
Unix: lsof: Command not found
Instead try
/usr/sbin/lsof .nfsC23D
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
tail
1257
robh 0r VREG
176
,
6
5
3000753
.nfsC23D
%kill