[samba4] Add README.downgrade to the main samba4 package

[abbra]

commit f7887a752b57f15467f94ac2afae8809f2609d98
Author: Alexander Bokovoy <abokovoy at redhat.com>
Date:   Mon Jul 16 12:17:37 2012 +0300

    Add README.downgrade to the main samba4 package

 README.downgrade |   29 +++++++++++++++++++++++++++++
 samba4.spec      |    9 ++++++++-
 2 files changed, 37 insertions(+), 1 deletions(-)
---
diff --git a/README.downgrade b/README.downgrade
new file mode 100644
index 0000000..5cb0aaa
--- /dev/null
+++ b/README.downgrade
@@ -0,0 +1,29 @@
+Downgrading Samba
+=================
+
+Short version: data-preserving downgrades between Samba versions are not supported
+
+Long version:
+With Samba development there are cases when on-disk database format evolves.
+In general, Samba Team attempts to maintain forward compatibility and
+automatically upgrade databases during runtime when requires.
+However, when downgrade is required Samba will not perform downgrade to
+existing databases. It may be impossible if new features that caused database
+upgrade are in use. Thus, one needs to consider a downgrade procedure before
+actually downgrading Samba setup.
+
+Please always perform back up prior both upgrading and downgrading across major
+version changes. Restoring database files is easiest and simplest way to get to
+previously working setup.
+
+Easiest way to downgrade is to remove all created databases and start from scratch.
+This means losing all authentication and domain relationship data, as well as
+user databases (in case of tdb storage), printers, registry settings, and winbindd
+caches.
+
+Remove databases in following locations:
+/var/lib/samba/*.tdb
+/var/lib/samba/private/*.tdb
+
+In particular, registry settings are known to prevent running downgraded versions
+(Samba 4 to Samba 3) as registry format has changed between Samba 3 and Samba 4.
diff --git a/samba4.spec b/samba4.spec
index 3eab836..3854aa3 100644
--- a/samba4.spec
+++ b/samba4.spec
@@ -1,4 +1,4 @@
-%define main_release 126
+%define main_release 127
 
 %define samba_version 4.0.0
 %define talloc_version 2.0.7
@@ -77,6 +77,7 @@ Source101: smb.init
 Source102: winbind.init
 
 Source200: README.dc
+Source201: README.downgrade
 
 Patch1: samba4-libpdb-soversion.patch
 
@@ -515,6 +516,8 @@ install -m 0644 %{SOURCE200} %{buildroot}%{_defaultdocdir}/%{name}/README.dc
 install -m 0644 %{SOURCE200} %{buildroot}%{_defaultdocdir}/%{name}/README.dc-libs
 %endif
 
+install -m 0644 %{SOURCE201} %{buildroot}%{_defaultdocdir}/%{name}/README.downgrade
+
 %if 0%{?fedora} > 15 || 0%{?rhel} > 6
 install -d -m 0755 %{buildroot}%{_unitdir}
 for i in nmb smb winbind ; do
@@ -700,6 +703,7 @@ rm -rf %{buildroot}
 %{_initrddir}/nmb
 %{_initrddir}/smb
 %endif
+%doc %{_defaultdocdir}/%{name}/README.downgrade
 
 %files libs
 %defattr(-,root,root)
@@ -1277,6 +1281,9 @@ rm -rf %{buildroot}
 %endif # with_libwbclient
 
 %changelog
+* Mon Jul 16 2012 Alexander Bokovoy <abokovoy at redhat.com> - 2:4.0.0-127.beta2
+- Add README.downgrade to samba4 package
+
 * Thu Jul 12 2012 Andreas Schneider <asn at redhat.com> - 2:4.0.0-126.beta2
 - Update to Samba 4.0.0 beta3.
 - Add requirement for samba4-python in samba4-dc.