Subject: problems unmounting an apparently non-busy filesystem
To: NetBSD-current Discussion List <current-users@NetBSD.ORG>
From: Greg A. Woods <>
List: current-users
Date: 04/09/2001 15:07:10
Does anyone know if there are any hidden reasons why a filesystem would
be marked busy even when nothing is apparently using it?

I have a filesystem I'd like to unmount and newfs but the kernel's
refusing to allow me to do it:

	# umount /altroot 
	unmount: /altroot: Device busy

Nothing is using the filesystem:

	# fstat -f /altroot
	USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W

(why does fstat print the report header when there's no output?)

I did just successfully unmount another non-busy filesystem, so the
whole kernel's not hosed....

The only unique things about this filesystem vs. the one that was
successfully unmounted are:  a) that it was previously underneath
another mount point (/altroot/var), the filesystem that successfully
unmounted) and; b) it was previously exported via NFS.

FYI this system is running NetBSD/i386-1.5T from 2001/03/24 sources.

On a mostly un-related note, why does mountd not discover remote mounts
after it has been restarted?

	# showmount -a
	All mount points on localhost:

							Greg A. Woods

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