Well, I didn't think my disk was going to fill up again, but it did last night! So I was able to test out the behavior. It was exactly as Stephen described: [No backup available] /home/eric $ dir ~/xemacs/backups/*secondary* ls: /home/eric/xemacs/backups/*secondary*: No such file or directory [Original file] /home/eric $ dir second* -rwxr--r-- 1 eric eric 33129 Oct 28 21:26 secondarymarket.txt [Try to save secondarymarket.txt] Writing file: No space left on device, /home/eric/secondarymarket.txt [Original file is 0 length] /home/eric $ dir second* -rw-r--r-- 1 eric eric 0 Nov 13 18:55 secondarymarket.txt [But backup is there!] /home/eric $ dir ~/xemacs/backups/*secondary* -rwxr--r-- 1 eric eric 33129 Oct 28 21:26 /home/eric/xemacs/backups/!home!eric!secondarymarket.txt.~1~ Thanks Stephen! Eric