upgrades across samba3-alpha releases

[Kristis Makris]

Hello,

I'm wondering how upgrades from the samba3-alphaXX releases could
possibly affect the way the underlying data are used by samba in the
future. I'm currently using samba3-alpha23+LDAP, and I'm trying to
backup all the data samba needs to function with future releases. For
example, I know I need to be backing up secrets.tdb as it contains the
domain SID, but what happens if the data structure used to define the
format of the secrets.tdb file changes ? Other than backing up the
entire ~/prefix location of the installed samba3, and LDAP, what else
should be backed up ?

Is there currently a generic "samba-config-migrate" tool that can be
used to upgrade the contents of such binary files from one release
version to another, converting the data as needed? Perhaps there's not
much to backup other than the SID itself, but I have not been able to
find any documentation related to this issue.

It looks like necessary migration steps between alphas are currently
provided, and that's a greatly appreciated, good practise. For example,
as noted in http://master.samba.org/samba/ftp/alpha/WHATSNEW.txt alpha23
required the pdbedit utility to transfer group mapping if one was
running 3_0 alphas with LDAP as a backend. My question is, will such
migration steps always be provided, between alphas, or was it common in
the past to make bigger jumps between developer releases that break
compatibility? How confident should I be that when samba_3_stable is
released, an upgrade from a samba3-alphaXX won't break ?

Thanks,
Kristis