Description of problem: NFS exported filesystem can not be unmuont even though all nfs-clients unmount the share. Version-Release number of selected component (if applicable): RHEL4.7 (kernel 2.6.9-78) nfs-utils-1.0.6-87.EL4 How reproducible: Always Steps to Reproduce: 1. Setup NFS server. mount /nfs. setup /etc/exports dir. Start nfs daemon. 2. Mount the NFS share from NFS client. # mount NFS_Server:/nfs /mnt This NFS mount succesful. 3. Umount the NFS share from NFS client. # umount /mnt This NFS umount succesful. 4. Umount /nfs on NFS Server. # umount /nfs Actual results: Umount fail with following message. # umount /nfs umount: /nfs: device is busy umount: /nfs: device is busy Expected results: umount successful without error message. Workaround: (1) umount -l /nfs (2) /etc/init.d/nfs restart, then umount /nfs Additional info: When umount failed, lsof shows no process accessing /nfs fuser shows no process accessing /nfs
Hello, Another workaround that I just found was, remove export entry in kernel before issue umount. # exportfs -au # umount /nfs So, my question would be, " Umount a file system while it was exported by NFS got faild. Is this a bug or expected? " Thanks
This is expected. An actively exported a filesystem has an active reference and cannot be unmounted. I'm going to close this as NOTABUG. Please reopen it if you have further questions.