Once or twice a week my amanda backups are failing when a dumper exits
on signal 6, SIGABRT:

   Jun  5 23:27:38 scotch kernel: pid 82566 (dumper), uid 0: exited on signal 6
   Jun  8 19:53:43 scotch kernel: pid 96672 (dumper), uid 0: exited on signal 6

In looking at the source there clearly are calls to abort() in several
places. I'm assuming that there is an overflow problem with file
descriptors, that 4294967295 isn't a valid FD?

  driver: event_register: Invalid file descriptor 4294967295

I'm running FreeBSD 6.3 with Amanda 2.5.1p3 from ports. 

There isn't much information in the log:

INFO taper tape offsite-017 kb 0 fm 0 [OK]
SUCCESS dumper snow /project/Snow 20080608 0 [sec 2958.318 kb 3252861 kps 
1099.6 orig-kb 7477040]
WARNING driver chunker4 pid 97080 exited with signal 1
WARNING driver chunker8 pid 96979 exited with signal 1
WARNING driver chunker7 pid 96977 exited with signal 1
WARNING driver chunker6 pid 96976 exited with signal 1
WARNING driver chunker5 pid 96973 exited with signal 1
WARNING driver chunker3 pid 96971 exited with signal 1
WARNING driver chunker2 pid 96970 exited with signal 1
WARNING driver chunker1 pid 96969 exited with signal 1
WARNING driver chunker0 pid 96968 exited with signal 1
WARNING driver dumper8 pid 96676 exited with signal 1
WARNING driver dumper7 pid 96675 exited with signal 1
WARNING driver dumper6 pid 96674 exited with signal 1
WARNING driver dumper5 pid 96673 exited with signal 1
WARNING driver dumper3 pid 96671 exited with signal 1
WARNING driver dumper2 pid 96670 exited with signal 1
WARNING driver dumper1 pid 96669 exited with signal 1
WARNING driver dumper0 pid 96668 exited with signal 1

There is a bit more info in the amdump log:

chunker: pid 97080 executable chunker4 version 2.5.1p3
driver: result time 2994.072 from chunker4: PORT 50035
driver: event_register: Invalid file descriptor 4294967295
driver: send-cmd time 2994.118 to dumper0: QUIT
driver: send-cmd time 2994.118 to chunker0: QUIT
driver: send-cmd time 2994.118 to dumper1: QUIT
driver: send-cmd time 2994.118 to chunker1: QUIT
driver: send-cmd time 2994.118 to dumper2: QUIT
driver: send-cmd time 2994.118 to chunker2: QUIT
driver: send-cmd time 2994.118 to dumper3: QUIT
driver: send-cmd time 2994.119 to chunker3: QUIT
driver: send-cmd time 2994.119 to dumper5: QUIT
driver: send-cmd time 2994.119 to chunker5: QUIT
driver: send-cmd time 2994.119 to dumper6: QUIT
driver: send-cmd time 2994.119 to chunker6: QUIT
driver: send-cmd time 2994.119 to dumper7: QUIT
driver: send-cmd time 2994.119 to chunker7: QUIT
driver: send-cmd time 2994.119 to dumper8: QUIT
driver: send-cmd time 2994.119 to chunker8: QUIT
driver: send-cmd time 2994.119 to dumper9: QUIT
driver: send-cmd time 2994.119 to chunker9: QUIT
driver: send-cmd time 2994.119 to taper: QUIT
driver: dumper4 pid 96672 exited with signal 6
taper: DONE [idle wait: 2916.293 secs]
taper: writing end marker. [offsite-017 OK kb 0 fm 0]
driver: sending signal 1 to dumper0 pid 96668
driver: sending signal 1 to chunker0 pid 96968
driver: sending signal 1 to dumper1 pid 96669
driver: sending signal 1 to chunker1 pid 96969
driver: sending signal 1 to dumper2 pid 96670
driver: sending signal 1 to chunker2 pid 96970
driver: sending signal 1 to dumper3 pid 96671
driver: sending signal 1 to chunker3 pid 96971
driver: sending signal 1 to dumper5 pid 96673
driver: sending signal 1 to chunker5 pid 96973
driver: sending signal 1 to dumper6 pid 96674
driver: sending signal 1 to chunker6 pid 96976
driver: sending signal 1 to dumper7 pid 96675
driver: sending signal 1 to chunker7 pid 96977
driver: sending signal 1 to dumper8 pid 96676
driver: sending signal 1 to chunker8 pid 96979
driver: chunker4 pid 97080 exited with signal 1
driver: chunker8 pid 96979 exited with signal 1
driver: chunker7 pid 96977 exited with signal 1
driver: chunker6 pid 96976 exited with signal 1
driver: chunker5 pid 96973 exited with signal 1
driver: chunker3 pid 96971 exited with signal 1
driver: chunker2 pid 96970 exited with signal 1
driver: chunker1 pid 96969 exited with signal 1
driver: chunker0 pid 96968 exited with signal 1
driver: dumper8 pid 96676 exited with signal 1
driver: dumper7 pid 96675 exited with signal 1
driver: dumper6 pid 96674 exited with signal 1
driver: dumper5 pid 96673 exited with signal 1
driver: dumper3 pid 96671 exited with signal 1
driver: dumper2 pid 96670 exited with signal 1
driver: dumper1 pid 96669 exited with signal 1
driver: dumper0 pid 96668 exited with signal 1