This is a success story, in case anyone moves their NIS server and finds,
to their dismay, duplicate amanda entries in their passwd file. One of them
has to go. The problem is that one of the servers may have depended on it...

I had such a machine: it  kept failing its self-check.

This was after a duplicate passwd entry for amanda was found.

[amanda@amanda ~]$ amcheck Daily
Amanda Tape Server Host Check
-----------------------------
Holding disk /var/tmp/amanda: 14875232 KB disk space available, that's plenty
amcheck-server: slot 17: date 20060128 label Daily017 (exact label match)
NOTE: skipping tape-writable test
Tape Daily017 label ok
NOTE: info dir /var/lib/amanda/Daily/curinfo/nept.gc.cuny.edu: does not exist
NOTE: index dir /var/lib/amanda/Daily/index/nept.gc.cuny.edu: does not exist
Server check took 36.012 seconds

Amanda Backup Client Hosts Check
--------------------------------
WARNING: nept.gc.cuny.edu: selfcheck request timed out.  Host down?
Client check: 8 hosts checked in 30.142 seconds, 1 problem found

(brought to you by Amanda 2.4.4p3)
[amanda@amanda ~]$

After removing it, and looking at the documentation, I was directed to look at
/tmp/amanda

But this directory was owned by the former amanda, now an orphaned UID.

So I removed /tmp/amanda

After this I had a missing gnutar-lists subdirectory in /usr/local/var/amanda
Easy enough to fix

A third amcheck Daily resulted in success!

Amanda Tape Server Host Check
-----------------------------
Holding disk /var/tmp/amanda: 14875100 KB disk space available, that's plenty
amcheck-server: slot 17: date 20060128 label Daily017 (exact label match)
NOTE: skipping tape-writable test
Tape Daily017 label ok
NOTE: info dir /var/lib/amanda/Daily/curinfo/nept.gc.cuny.edu: does not exist
NOTE: index dir /var/lib/amanda/Daily/index/nept.gc.cuny.edu: does not exist
Server check took 35.343 seconds

Amanda Backup Client Hosts Check
--------------------------------
Client check: 8 hosts checked in 0.988 seconds, 0 problems found

(brought to you by Amanda 2.4.4p3)
[amanda@amanda ~]$