Kang Sun
2004-Jul-26 19:35 UTC
[Samba] Migration NT4 PDC to Smb3/LDAP/TOOLS: A Success Procedure
Greetings,
After a few weeks trying, I figured out how to migrate from NT4 PDC to
Samba-3/LDAP/SMBLDAP-TOOLS, at least in my case.
I will just explain my setup and my understanding why it works and why
it fails. I hope it is helpful to others who are in the same situation as I
was.
Basic Setup:
OS: Fedora-2 (FC2)
samba-3.0.3 that comes with FC2.
openldap-2.1.29 that comes with FC2.
smbldap-tools that comes with samba-3.0.3
Basic guide:
Samba-3 by Examples Chapter 6 and Chapter 8
Steps:
*** Using a faked domain for the testing so it won't interfere the
normal network ****
1. Follow Example 6.3.1 to configure /etc/openldap/slapd.conf
Mine is the same except the following specific.
suffix "dc=ab,dc=com"
rootdn "cn=Manager,dc=ab,dc=com"
rootpw not24get
2. Follow Example 6.3.2 to configure /etc/ldap.conf
Here is my configuration for /etc/ldap.conf
host 127.0.0.1
base dc=ab,dc=com
ssl no
pam_password md5
Note I did not turn on any of the nss directives. I think by default,
the right nss is used.
3. PAM and NSS Client Configuration
On FC2 you can simply run
authoconfig
and choose Cache,
[*] Cache Information [*] Use LDAP
[*] Use MD5 Passwords [*] Use Shadow Passwords
[*] Use LDAP Authentication
Note: This step tells the Unix system to use LDAP for all the
authetication.
After you exit from authconfig, NSCD (NS cache daemon) will
start.
/etc/nsswitch.conf is modified to let passwd/group resolved
by ldap.
** DO NOT LOGOUT BEFORE YOU STARTED OPENLDAP**
or you might not be able to login again since not LDAP
server is running.
4. Samba-3 Configuration
Make /etc/samba/smb.conf according to Examples 6.3.4 6.3.5
6.4.3, 6.4.4 and your organization's particular situation.
A few entries are differet in my /etc/samba/smb.conf
[global]
workgroup = ab
netbios name = PDC
passdb backend = ldapsam:ldap://127.0.0.1/
admin users= @"Domain Admins"
encrypt passwords = Yes
obey pam restrictions = No
ldap passwd sync = Yes
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
mangling method = hash2
domain master = Yes
os level = 65
ldap ssl = No
# I am not sure if all the above are needed, but it worked
for me
ldap suffix = dc=ab,dc=com
ldap machine suffix = ou=People
ldap user suffix = ou=Users
...
Note: I use People as the machine holder since I was told that samba
looks for machines in People's group.
Users seems to hold users fine!
Test and start samba as instructed.
5. Configure the smbldap-tools.
Configure and install smbldap-tools as in the guide, rembmer to
compile and install MKNTPWD.
Since I use People as holder for computers, I need to make the
following changes in smbldap_conf.pm
$computersou = q(People);
Forget about the session on LDMAP entries for now, they will be
created as the migration goes on.
6. Populate the ldap database
Start ldap by /etc/init.d/ldap start
./smbldap-populate.pl
Test it as suggested in the guide.
Create a user and test it with 'id <username>'. If you see
it belong
to group "Domain Users", the pam/nss authorization is working.
** Configure auto start of ldap server by '(cd /etc/rc3.d; ln -s
../init.d/ldap S48ldap)' or something like it. **
The above step is imporant to ensure you are able to login after the
machine restarted.
Restart sshd '/etc/init.d/sshd restart' to make it aware of the
new
authentication scheme and ssh to see the new user you created in ldap
server.
7. Start the samba server and hopefully you system is a PDC for a faked
domain.
****************** Now for the Migration
********************************************
1. Shutdown the ldap and samba daemon.
/etc/init.d/ldap stop
/etc/init.d/smb stop
2. Editing /etc/samba/smb.conf
domain master = No
workgroup = <REAL domain>
add user script = /var/lib/samba/sbin/smbldap-useradd.pl -m
"%u"
Note: this ensures that it start as the samba will start as a BDC in the
REAL domain.
**** IMPORTANT: "add user script" should not create Windows
account
during Migration.
The migration process only expect a Posix account and will
create a Windows account as it migrates from the old NT4 domain.
So Remove the "-a" option from smbldap-useradd.p script.
Otherwise you will see "user exists" and passwords will not be
migrated.
3. Clean up all the previous ldap and samba entries.
rm -rf /var/lib/ldap/* # clean up the ldap database
rm -f /var/cache/samba/* # clean up the cached samba entries.
rm -f /etc/samb/*.tdb # clean up the all exiting tdb
Note: ** Cleaning up is needed whenever you change your configuration,
otherwise you will have unexpected result. **
4. Get your Domain SID as instructed
net rpc getsid -S <PDC server> -W <Real domain>
Also run "smbpasswd -w not24get"
Run "tdbdump /etc/samba/secrets.tdb" to see what is in this tdb.
5. Preload the database
Refer to Example 8.3.1
With several trial I realized that I need to reploaded a few more
entries to make the migration work!
In addtion to the entries suggested, I made additional entries.
*** replace the domain part of SID with the SID you obtain from above
step ***
dn: ou=Users,dc=ab,dc=com
objectClass: top
objectClass: organizationalUnit
ou: Users
structuralObjectClass: organizationalUnit
Note: This is needed since we hold all users in Users group
dn: cn=Domain Admins,ou=Groups,dc=ab,dc=com
objectClass: posixGroup
objectClass: sambaGroupMapping
cn: Domain Admins
gidNumber: 512
structuralObjectClass: posixGroup
entryUUID: d5c6a642-736b-1028-828a-f4f139c67fb5
sambaSID: S-1-5-21-72881033-379349262-1855928443-512
sambaGroupType: 2
displayName: Domain Admins
description: Designated administrators of the domain
entryCSN: 2004072616:23:12Z#0x0002#0#0000
Note: smbtools assuming the "Domain Admins" group is mapped to GID
512.
Without this entry,
the migration will create a "Domain Admins" group with a
random
GID
dn: cn=Domain Users,ou=Groups,dc=ab,dc=com
objectClass: posixGroup
objectClass: sambaGroupMapping
cn: Domain Users
gidNumber: 513
structuralObjectClass: posixGroup
entryUUID: d792f890-736b-1028-828b-f4f139c67fb5
sambaSID: S-1-5-21-72881033-379349262-1855928443-513
sambaGroupType: 2
displayName: Domain Users
description: All domain users
entryCSN: 2004072616:23:15Z#0x0002#0#0000
Note: smbldap-tools expected all "Domain Users" being mapped to GID
513.
** This entry is important, or you will get "Group 513 does not
exist" error during migration. **
dn: cn=Domain Guests,ou=Groups,dc=ab,dc=com
objectClass: posixGroup
objectClass: sambaGroupMapping
cn: Domain Guests
gidNumber: 514
structuralObjectClass: posixGroup
entryUUID: d95eacaa-736b-1028-828c-f4f139c67fb5
creatorsName: cn=Manager,dc=ab,dc=com
createTimestamp: 20040726162318Z
sambaSID: S-1-5-21-72881033-379349262-1855928443-514
sambaGroupType: 2
displayName: Domain Guests
description: All domain guests
entryCSN: 2004072616:23:18Z#0x0002#0#0000
Note: I am not sure how important this is.
dn: uid=Administrator,ou=Users,dc=ab,dc=com
objectClass: top
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: sambaSamAccount
cn: Administrator
sn: Administrator
uid: Administrator
uidNumber: 0
gidNumber: 512
homeDirectory: /u/Administrator
loginShell: /bin/tcsh
gecos: System User
structuralObjectClass: inetOrgPerson
entryUUID: eb4d3030-736b-1028-8296-f4f139c67fb5
sambaSID: S-1-5-21-72881033-379349262-1855928443-500
sambaPrimaryGroupSID: S-1-5-21-72881033-379349262-1855928443-512
description: Built-in account for administering the computer/domain
sambaLogonTime: 1090857052
sambaLogoffTime: 981830074
sambaLMPassword: A97D5AFE0D3EF79944CBCFC86460DB9E
sambaNTPassword: 015B5326F969E4741241A45F1C734BAD
sambaPwdLastSet: 1052497723
sambaAcctFlags: [UX ]
entryCSN: 2004072616:23:49Z#0x0001#0#0000
Note: smbldap-tools expects Administrator account has UID 0 and GID 512.
Without this entry, the migration process will create an unprivileged
Administrator account.
6. Now run the preload
slapadd -v -l preload.LDIF
Note: ldap daemon should be up at this point.
chown ldap:ldap /var/lib/ldap/*
Note: This chnage the owner and group to ldap.
/etc/init.d/ldap start
7. Join your server into domain
net rpc join BDC -S <PDC Server> -W <REAL domain> -U
Administrator&<admin passwd>
Note, samba should not run at this time. Otherwise you will get "Cannot
Set Creds" error.
8. Vampiring ....
net rpc vampire -S <PDC server> -U administrator%<admin
passwd>
Note, samba should not run at this time. Otherwise you will get "Cannot
Set Creds" error.
Let me know if I missed any step.
Good luck!
--- Kang Sun
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