How do I troubleshoot an JFS_FS_FULL error?

I was looking at the errpt and noticed the below listed error.  I am guessing I need to clear out space in my /tmp directory but when I do a "df", only 20% is used.  Thus, I am a bit confused about the error, its source, and what I should do about.  Can someone please help?  -Thanks


LABEL:          JFS_FS_FULL
IDENTIFIER:     369D049B
                                                                       
Date/Time:       Mon Jan 15 09:33:36 EST 2007
Sequence Number: 3775615
Machine Id:    
Node Id:        
Class:           O
Type:            INFO
Resource Name:   SYSPFS
                                                                       
Description
UNABLE TO ALLOCATE SPACE IN FILE SYSTEM
                                                                       
Probable Causes
FILE SYSTEM FULL
                                                                       
        Recommended Actions
        USE FUSER UTILITY TO LOCATE UNLINKED FILES STILL REFERENCED
        INCREASE THE SIZE OF THE ASSOCIATED FILE SYSTEM
        REMOVE UNNECESSARY DATA FROM FILE SYSTEM
                                                                       
Detail Data
MAJOR/MINOR DEVICE NUMBER
000A 0007
FILE SYSTEM DEVICE AND MOUNT POINT
/dev/hd3, /tmpStart Free Trial