Dump(8) does not do incremental

[Olivier Nicole]

Hello,

Is there any reason why dump would not do incremental when used with -f -?

I do a full dump:

# ssh root at 192.41.170.38 "dump -f - -L /dev/da1s1d" | restore -r -f -
Password:
  DUMP: Date of this level 0 dump: Thu Apr  2 10:48:58 2015
  DUMP: Date of last level 0 dump: the epoch

followed by an incremental one:

# ssh root at 192.41.170.38 "dump -1 -f - -L /dev/da1s1d" | restore -r -f -
Password:
  DUMP: Date of this level 1 dump: Thu Apr  2 12:35:23 2015
  DUMP: Date of last level 0 dump: the epoch

The level 0 is always shown at the epoch.

I may be missing something but I don't see what.

Thank you,

Olivier