i386/57480: Removing very large files using rm doesn't show the space being unallocated by the kernel and df.

[Shon Elliott]

>Number:         57480
>Category:       i386
>Synopsis:       Removing very large files using rm doesn't show the space being unallocated by the kernel and df.
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Wed Oct 01 14:40:09 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Shon Elliott
>Release:        FreeBSD 4.8-RELEASE-p4 i386
>Organization:
MiS Productions
>Environment:
System: FreeBSD tsunami.misproductions.com 4.8-RELEASE-p4 FreeBSD 4.8-RELEASE-p4 #23: Thu Sep 11 10:26:11 PDT 2003 root at tsunami.misproductions.com:/usr/obj/usr/src/sys/TSUNAMI i386


	AMD K6-2 400, FreeBSD 4.8-RELEASE-p4, 192M Memory, 17GB HD. SiS Based board.
>Description:
	When having a large file, sayt about 800 megs, and using rm on the file, it will be removed, however the space 
        occupied by that file will not be released by the kernel/filesystem  or shown by df. This has been noticed for UFS
        partitions, and not been extensively tested by me on any other filesystem.
>How-To-Repeat:
	Create a large file, say 800 megs. then remove said file using the rm command. 
>Fix:

	To work around the problem, you can use the following commands:
        echo "." > filename.ext 
        rm filename.ext

	That will cause the system to correctly report the freed space. If the UFS system using rm doesn't clear the space,
        the only way to recover that space seems to be a restart of the entire system.


>Release-Note:
>Audit-Trail:
>Unformatted: