umount problem

[peterchu]

I have a problem that happened at two RH linux server , but can't find the solution at linux forum , so I try to post the question there, very thanks if you can help .

I have two hosts - host A export a path for host B , host B mount this path , it seems work fine , if I use "df" on host B like below
hostA:/tmp/EDP /home/peter/EDP ,

However , when the user in host B read the file , then it will hang , I have to re-mount it , but if I read the file again , it will hang again. so I have already mount the path many times, if I use "df" , it display

hostA:/tmp/EDP /home/peter/EDP
hostA:/tmp/EDP /home/peter/EDP
hostA:/tmp/EDP /home/peter/EDP
"
"
I tried to reboot the host A , it seems the path can't umount , therefore other path can't mount to it , I tried many method like "fuser" , but no process found , and also tried "umount -f" , the message as below,

[root@peter tmp]# umount -f /home/peter/EDP
umount2: Device or resource busy
umount: /home/peter/EDP: Illegal seek
umount2: Device or resource busy

could suggest how can I ACTUALLY umount the path ? thx

[peterchu]

this is my post at linux forum , because it is urgent case , so I have post both forum , sorry for any inconvenience caused.

[peterchu]

this is my post at linux forum , because it is urgent case , so I have post both forum , sorry for any inconvenience caused.

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=579731