drop a column

I need to drop a column in a huge table( total 856941 rows and rows size 27). To avoid long transaction, I set logging status to no logging. After load almost 20000 rows, I got the error: 222: Cannot write to temporary file for new table . 131: ISAM error: no free disk space At the begining I thought maybe that was because temp dbspaces were full. But then I run again and found although temp dbspace is almost 360 MB empty all the time, I still got the same error. My question is: It use temp dbspaces or /tmp file system? In my config file, DBSPACETEMP already set to temp dbspaces. I am using online 7.14 UD1 on HP-UX 10.20. Thanks in advance. Vivian vyao@dehavilland.ca