Bug 8838

Summary: NFS server does not release device after it is unmounted.
Product: [Retired] Red Hat Linux Reporter: Joseph Kotran <jkotran>
Component: nfs-utilsAssignee: Michael K. Johnson <johnsonm>
Status: CLOSED CURRENTRELEASE QA Contact:
Severity: high Docs Contact:
Priority: medium    
Version: 7.0   
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Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2003-01-24 20:03:58 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Joseph Kotran 2000-01-25 15:19:03 UTC 
To recreate this bug you may do the following:

o Mount a CD-ROM
o Share the CD-ROM mount point to the network
o NFS mount the shared CD-ROM on a remote client
o On the remote client umount the NFS share

At this point you will not be able umount the CD-ROM on the nfs server
until you shutdown the nfs daemons.  The process that I have outlined
worked on all Red Hat releases up until 5.2.  Since 6.0 you have to
shutdown the nfs server to umount the CD-ROM.  I have recreated this
behavior on i386, Sparc, and Sparc64 platforms.

Regards,

Joe Kotran
Comment 1 Jeremy Katz 2000-01-28 01:20:59 UTC 
This is a difference between 2.2.x + knfsd and 2.0.x + user-space nfsd, and is
the expected behavior.  Cross-reference this message on linux-kernel,
http://www.tux.org/hypermail/linux-kernel/1999week18/0802.html
Comment 2 gozerian 2000-02-11 18:54:59 UTC 
Same here on stock 6.1, very annoying...
Comment 3 Alan Cox 2000-02-17 15:31:59 UTC 
Verified here. knfsd seems to be hanging on to handles to mount
points. It may be a feature but its not a nice one
Comment 4 Cristian Gafton 2000-08-09 02:34:34 UTC 
assigned to johnsonm
Comment 5 Stephen John Smoogen 2003-01-24 20:03:58 UTC 
Bug 8838 has been closed because it seems fixed with the NFS in 7.2/7.3/8.0
releases. The additional step that you have to do is to stop nfs from exporting
/mnt/cdrom and then you can unmount /mnt/cdrom safely.