Someone may already know about this, but using gtar > 1.15.1 and
amanda < 2.5.1 will not work very well.

The format of the "listed incremental" file has changed.  Among other
things, the entries are now separated by '\0' "null" bytes rather than
newlines.  [I'm not exactly sure why since it doesn't save any space
and I don't think '\n' is a valid character in a posix file name].

This causes trouble for amanda < 2.5.1 which tries to read in the
"old" snapshot file and copy it to a new one in a fgets/fputs loop
which explicitly appends a newline to the copy whether there was one
in the original or not.  With the old format (gnutar <= 1.15.1), this
was not a problem since it used newlines.

Not only does amanda add newlines (which gtar 1.20 chokes on because
it explicitly looks for '\0' characters and dies a fatal death on
seeing '\n' instead - see read_unsigned_num() in src/incremen.c), but
it also truncates the file because amanda stops processing the file
early due to the null bytes.


As a result, you will see things like so...

  yoyoma      / lev 0 FAILED [dumps too big, 1 KB, but no incremental estimate]

and/or

  planner: disk furble:/usr, estimate of level 1 failed: -1.


There are some other oddities that I haven't fully figured out yet
(I'm not sure they are fatal), but without patching
client-src/sendbackup-gnutar.c to do what 2.5.1 and later does (or
updating amanda), this problem is a showstopper.

This could be particularly troublesome for clients that you can't
update to a newer amanda (but more than likely in that case, you won't
be updating them to gnutar 1.20 either).

There was a zmanda wiki page that described issues with various gnutar
and amanda version combinations, but I can't seem to find it at the
moment (the search doesn't turn it up that I saw).

If someone finds it, let me know and I'll try to see that this info
gets added.


Separate issue, but worth a mention...

Note also that changing from gnutar <= 1.15.1 to a later version (if
you already have incremental dump files in your gnutar-lists
directories) will cause some very large incremental dumps to happen
because of some details of the format change that I won't go into
here.