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diff --git a/docs/howto/NT4Migration.xml b/docs/howto/NT4Migration.xml new file mode 100644 index 0000000000..5cb4e0c117 --- /dev/null +++ b/docs/howto/NT4Migration.xml @@ -0,0 +1,525 @@ +<chapter id="NT4Migration"> +<chapterinfo> + &author.jht; + <pubdate>April 3, 2003</pubdate> +</chapterinfo> + +<title>Migration from NT4 PDC to Samba-3 PDC</title> + +<para> +This is a rough guide to assist those wishing to migrate from NT4 Domain Control to +Samba-3-based Domain Control. +</para> + +<sect1> +<title>Planning and Getting Started</title> + +<para> +In the IT world there is often a saying that all problems are encountered because of +poor planning. The corollary to this saying is that not all problems can be anticipated +and planned for. Then again, good planning will anticipate most show-stopper-type situations. +</para> + +<para> +Those wishing to migrate from MS Windows NT4 Domain Control to a Samba-3 Domain Control +environment would do well to develop a detailed migration plan. So here are a few pointers to +help migration get under way. +</para> + +<sect2> +<title>Objectives</title> + +<para> +The key objective for most organizations will be to make the migration from MS Windows NT4 +to Samba-3 Domain Control as painless as possible. One of the challenges you may experience +in your migration process may well be one of convincing management that the new environment +should remain in place. Many who have introduced open source technologies have experienced +pressure to return to a Microsoft-based platform solution at the first sign of trouble. +</para> + +<para> +Before attempting a migration to a Samba-3 controlled network, make every possible effort to +gain all-round commitment to the change. Know precisely <emphasis>why</emphasis> the change +is important for the organization. Possible motivations to make a change include: +</para> + +<itemizedlist> + <listitem><para>Improve network manageability.</para></listitem> + <listitem><para>Obtain better user level functionality.</para></listitem> + <listitem><para>Reduce network operating costs.</para></listitem> + <listitem><para>Reduce exposure caused by Microsoft withdrawal of NT4 support.</para></listitem> + <listitem><para>Avoid MS License 6 implications.</para></listitem> + <listitem><para>Reduce organization's dependency on Microsoft.</para></listitem> +</itemizedlist> + +<para> +Make sure everyone knows that Samba-3 is not MS Windows NT4. Samba-3 offers +an alternative solution that is both different from MS Windows NT4 and offers +advantages compared with it. Gain recognition that Samba-3 lacks many of the +features that Microsoft has promoted as core values in migration from MS Windows NT4 to +MS Windows 2000 and beyond (with or without Active Directory services). +</para> + +<para> +What are the features that Samba-3 cannot provide? +</para> + +<itemizedlist> + <listitem><para>Active Directory Server.</para></listitem> + <listitem><para>Group Policy Objects (in Active Directory).</para></listitem> + <listitem><para>Machine Policy Objects.</para></listitem> + <listitem><para>Logon Scripts in Active Directory.</para></listitem> + <listitem><para>Software Application and Access Controls in Active Directory.</para></listitem> +</itemizedlist> + +<para> +The features that Samba-3 does provide and that may be of compelling interest to your site +include: +</para> + +<itemizedlist> + <listitem><para>Lower cost of ownership.</para></listitem> + <listitem><para>Global availability of support with no strings attached.</para></listitem> + <listitem><para>Dynamic SMB Servers (can run more than one SMB/CIFS server per UNIX/Linux system).</para></listitem> + <listitem><para>Creation of on-the-fly logon scripts.</para></listitem> + <listitem><para>Creation of on-the-fly Policy Files.</para></listitem> + <listitem><para>Greater stability, reliability, performance and availability.</para></listitem> + <listitem><para>Manageability via an ssh connection.</para></listitem> + <listitem><para>Flexible choices of back-end authentication technologies (tdbsam, ldapsam, mysqlsam).</para></listitem> + <listitem><para>Ability to implement a full single-sign-on architecture.</para></listitem> + <listitem><para>Ability to distribute authentication systems for absolute minimum wide area network bandwidth demand.</para></listitem> +</itemizedlist> + +<para> +Before migrating a network from MS Windows NT4 to Samba-3, consider all necessary factors. Users +should be educated about changes they may experience so the change will be a welcome one +and not become an obstacle to the work they need to do. The following are factors that will +help ensure a successful migration: +</para> + +<sect3> +<title>Domain Layout</title> + +<para> +Samba-3 can be configured as a Domain Controller, a back-up Domain Controller (probably best called +a secondary controller), a Domain Member, or as a stand-alone Server. The Windows network security +domain context should be sized and scoped before implementation. Particular attention needs to be +paid to the location of the primary Domain Controller (PDC) as well as backup controllers (BDCs). +One way in which Samba-3 differs from Microsoft technology is that if one chooses to use an LDAP +authentication backend, then the same database can be used by several different domains. In a +complex organization, there can be a single LDAP database, which itself can be distributed (have +a master server and multiple slave servers) that can simultaneously serve multiple domains. +</para> + +<para> +From a design perspective, the number of users per server as well as the number of servers per +domain should be scaled taking into consideration server capacity and network bandwidth. +</para> + +<para> +A physical network segment may house several domains. Each may span multiple network segments. +Where domains span routed network segments, consider and test the performance implications of +the design and layout of a network. A centrally located Domain Controller that is designed to +serve multiple routed network segments may result in severe performance problems. Check the +response time (ping timing) between the remote segment and the PDC. If +it's long (more than 100 ms), +locate a backup controller (BDC) on the remote segment to serve as the local authentication and +access control server. +</para> +</sect3> + +<sect3> +<title>Server Share and Directory Layout</title> + +<para> +There are cardinal rules to effective network design that cannot be broken with impunity. +The most important rule: Simplicity is king in every well-controlled network. Every part of +the infrastructure must be managed; the more complex it is, the greater will be the demand +of keeping systems secure and functional. +</para> + +<para> +Keep in mind the nature of how data must be shared. Physical disk space layout should be considered +carefully. Some data must be backed up. The simpler the disk layout the easier it will be to +keep track of backup needs. Identify what backup media will meet your needs; consider backup to tape, +CD-ROM or (DVD-ROM), or other offline storage medium. Plan and implement for minimum +maintenance. Leave nothing to chance in your design; above all, do not leave backups to chance: +Backup, test, and validate every backup, create a disaster recovery plan and prove that it works. +</para> + +<para> +Users should be grouped according to data access control needs. File and directory access +is best controlled via group permissions and the use of the <quote>sticky bit</quote> on group controlled +directories may substantially avoid file access complaints from Samba share users. +</para> + +<para> +Inexperienced network administrators often attempt elaborate techniques to set access +controls on files, directories, shares, as well as in share definitions. +Keep your design and implementation simple and document your design extensively. Have others +audit your documentation. Do not create a complex mess that your successor will not understand. +Remember, job security through complex design and implementation may cause loss of operations +and downtime to users as the new administrator learns to untangle your knots. Keep access +controls simple and effective and make sure that users will never be interrupted by obtuse +complexity. +</para> +</sect3> + +<sect3> +<title>Logon Scripts</title> + +<para> +Logon scripts can help to ensure that all users gain the share and printer connections they need. +</para> + +<para> +Logon scripts can be created on-the-fly so all commands executed are specific to the +rights and privileges granted to the user. The preferred controls should be affected through +group membership so group information can be used to create a custom logon script using +the <smbconfoption><name>root preexec</name></smbconfoption> parameters to the <smbconfsection>NETLOGON</smbconfsection> share. +</para> + +<para> +Some sites prefer to use a tool such as <command>kixstart</command> to establish a controlled +user environment. In any case, you may wish to do a Google search for logon script process controls. +In particular, you may wish to explore the use of the Microsoft Knowledge Base article KB189105 that +deals with how to add printers without user intervention via the logon script process. +</para> +</sect3> + +<sect3> +<title>Profile Migration/Creation</title> + +<para> +User and Group Profiles may be migrated using the tools described in the section titled Desktop Profile +Management. +</para> + + +<para> +<indexterm><primary>SID</primary></indexterm> +Profiles may also be managed using the Samba-3 tool <command>profiles</command>. This tool allows +the MS Windows NT-style security identifiers (SIDs) that are stored inside the profile <filename>NTuser.DAT</filename> file +to be changed to the SID of the Samba-3 domain. +</para> +</sect3> + +<sect3> +<title>User and Group Accounts</title> + +<para> +It is possible to migrate all account settings from an MS Windows NT4 domain to Samba-3. Before +attempting to migrate user and group accounts, it is STRONGLY advised to create in Samba-3 the +groups that are present on the MS Windows NT4 domain <emphasis>AND</emphasis> to map them to +suitable UNIX/Linux groups. By following this simple advice, all user and group attributes +should migrate painlessly. +</para> +</sect3> + +</sect2> + +<sect2> +<title>Steps in Migration Process</title> + +<para> +The approximate migration process is described below. +</para> + +<itemizedlist> +<listitem><para> +You have an NT4 PDC that has the users, groups, policies and profiles to be migrated. +</para></listitem> + +<listitem><para> +Samba-3 set up as a DC with netlogon share, profile share, and so on. Configure the &smb.conf; file +to function as a BDC, i.e., <parameter>domain master = No</parameter>. +</para></listitem> +</itemizedlist> + +<procedure><title>The Account Migration Process</title> + <step><para> +<indexterm><primary>pdbedit</primary></indexterm> + Create a BDC account in the old NT4 domain for the Samba server using NT Server Manager.</para> + <substeps><step><para>Samba must not be running.</para></step></substeps></step> + + + <step><para> +<indexterm><primary>net</primary><secondary>rpc</secondary></indexterm> + <userinput>net rpc join -S <replaceable>NT4PDC</replaceable> -w <replaceable>DOMNAME</replaceable> -U Administrator%<replaceable>passwd</replaceable></userinput></para></step> + + <step><para><userinput>net rpc vampire -S <replaceable>NT4PDC</replaceable> -U administrator%<replaceable>passwd</replaceable></userinput></para></step> + + <step><para><userinput>pdbedit -L</userinput></para> + <substeps><step><para>Note &smbmdash; did the users migrate?</para></step></substeps> + </step> + + + <step><para> +<indexterm><primary>net</primary><secondary>groupmap</secondary></indexterm> +<indexterm><primary>initGroups.sh</primary></indexterm> + Now assign each of the UNIX groups to NT groups: + (It may be useful to copy this text to a script called <filename>initGroups.sh</filename>) + <smbfile name="initGroups.sh"> + <programlisting> +#!/bin/bash +#### Keep this as a shell script for future re-use + +# First assign well known domain global groups +net groupmap modify ntgroup="Domain Admins" unixgroup=root rid=512 +net groupmap modify ntgroup="Domain Users" unixgroup=users rid=513 +net groupmap modify ntgroup="Domain Guests" unixgroup=nobody rid=514 + +# Now for our added domain global groups +net groupmap add ntgroup="Designers" unixgroup=designers type=d rid=3200 +net groupmap add ntgroup="Engineers" unixgroup=engineers type=d rid=3210 +net groupmap add ntgroup="QA Team" unixgroup=qateam type=d rid=3220 +</programlisting> +</smbfile> + </para></step> + + <step><para><userinput>net groupmap list</userinput></para> + <substeps><step><para>Check that all groups are recognized.</para></step></substeps> + </step> +</procedure> + +<para> +Migrate all the profiles, then migrate all policy files. +</para> + +</sect2> +</sect1> + +<sect1> +<title>Migration Options</title> + +<para> +Sites that wish to migrate from MS Windows NT4 Domain Control to a Samba-based solution +generally fit into three basic categories. <link linkend="majtypes">Following table</link> shows the possibilities. +</para> + +<table frame="all" id="majtypes"><title>The Three Major Site Types</title> +<tgroup cols="2"> + <colspec align="left"/> + <colspec align="justify" colspec="1*"/> + <thead> + <row><entry>Number of Users</entry><entry>Description</entry></row> + </thead> + <tbody> + <row><entry>< 50</entry><entry><para>Want simple conversion with no pain.</para></entry></row> + <row><entry>50 - 250</entry><entry><para>Want new features, can manage some in-house complexity.</para></entry></row> + <row><entry>> 250</entry><entry><para>Solution/Implementation must scale well, complex needs. Cross-departmental decision process. Local expertise in most areas.</para></entry></row> + </tbody> +</tgroup> +</table> + +<sect2> +<title>Planning for Success</title> + +<para> +There are three basic choices for sites that intend to migrate from MS Windows NT4 +to Samba-3: +</para> + +<itemizedlist> + <listitem><para> + Simple conversion (total replacement). + </para></listitem> + + <listitem><para> + Upgraded conversion (could be one of integration). + </para></listitem> + + <listitem><para> + Complete redesign (completely new solution). + </para></listitem> +</itemizedlist> + +<para> +Minimize down-stream problems by: +</para> + +<itemizedlist> + <listitem><para> + Taking sufficient time. + </para></listitem> + + <listitem><para> + Avoiding Panic. + </para></listitem> + + <listitem><para> + Testing all assumptions. + </para></listitem> + + <listitem><para> + Testing the full roll-out program, including workstation deployment. + </para></listitem> +</itemizedlist> + +<para><link linkend="natconchoices">Following table</link> lists the conversion choices given the type of migration +being contemplated. +</para> + +<table frame="all" id="natconchoices"><title>Nature of the Conversion Choices</title> +<tgroup cols="3"> + <colspec align="justify" colwidth="1*"/> + <colspec align="justify" colwidth="1*"/> + <colspec align="justify" colwidth="1*"/> + <thead> + <row><entry>Simple</entry><entry>Upgraded</entry><entry>Redesign</entry></row> + </thead> + <tbody> + <row> + <entry><para>Make use of minimal OS specific features.</para></entry> + <entry><para>Translate NT4 features to new host OS features.</para></entry> + <entry><para>Decide:</para></entry> + </row> + <row> + <entry><para>Move all accounts from NT4 into Samba-3</para></entry> + <entry><para>Copy and improve</para></entry> + <entry><para>Authentication regime (database location and access)</para></entry> + </row> + <row> + <entry><para>Make least number of operational changes</para></entry> + <entry><para>Make progressive improvements</para></entry> + <entry><para>Desktop management methods</para></entry> + </row> + <row> + <entry><para>Take least amount of time to migrate</para></entry> + <entry><para>Minimize user impact</para></entry> + <entry><para>Better control of Desktops/Users</para></entry> + </row> + <row> + <entry><para>Live versus isolated conversion</para></entry> + <entry><para>Maximize functionality</para></entry> + <entry><para>Identify Needs for: <emphasis>Manageability, Scalability, Security, Availability</emphasis></para></entry> + </row> + <row> + <entry><para>Integrate Samba-3 then migrate while users are active, then change of control (swap out)</para></entry> + <entry><para>Take advantage of lower maintenance opportunity</para></entry> + <entry><para></para></entry> + </row> + </tbody> +</tgroup> +</table> +</sect2> + +<sect2> +<title>Samba-3 Implementation Choices</title> + +<variablelist> + <varlistentry><term>Authentication Database/Backend</term><listitem> + <para> + Samba-3 can use an external authentication backend: + </para> + + <para> + <itemizedlist> + <listitem><para>Winbind (external Samba or NT4/200x server).</para></listitem> + <listitem><para>External server could use Active Directory or NT4 Domain.</para></listitem> + <listitem><para>Can use pam_mkhomedir.so to auto-create home dirs.</para></listitem> + <listitem><para> + Samba-3 can use a local authentication backend: <parameter>smbpasswd, tdbsam, ldapsam, mysqlsam</parameter></para></listitem> + </itemizedlist> + </para> + </listitem></varlistentry> + + <varlistentry><term>Access Control Points</term><listitem> + <para> + Samba permits Access Control Points to be set: + </para> + <itemizedlist> + <listitem><para>On the share itself &smbmdash; using Share ACLs.</para></listitem> + <listitem><para>On the file system &smbmdash; using UNIX permissions on files and directories.</para> + <para>Note: Can enable Posix ACLs in file system also.</para></listitem> + <listitem><para>Through Samba share parameters &smbmdash; not recommended except as last resort.</para></listitem> + </itemizedlist> + </listitem> + </varlistentry> + + <varlistentry><term>Policies (migrate or create new ones)</term><listitem> + <para> + Exercise great caution when affecting registry changes, use the right tool and be aware + that changes made through NT4-style <filename>NTConfig.POL</filename> files can leave + permanent changes. + </para> + <itemizedlist> + <listitem><para>Using Group Policy Editor (NT4).</para></listitem> + <listitem><para>Watch out for Tattoo effect.</para></listitem> + </itemizedlist> + </listitem> + </varlistentry> + + <varlistentry><term>User and Group Profiles</term><listitem> + <para> + Platform-specific so use platform tool to change from a Local to a Roaming profile. + Can use new profiles tool to change SIDs (<filename>NTUser.DAT</filename>). + </para> + </listitem> + </varlistentry> + + <varlistentry><term>Logon Scripts</term><listitem> + <para> + Know how they work. + </para> + </listitem> + </varlistentry> + + + <varlistentry><term>User and Group Mapping to UNIX/Linux</term><listitem> + <para> +<indexterm><primary>pdbedit</primary></indexterm> + User and Group mapping code is new. Many problems have been experienced as network administrators + who are familiar with Samba-2.2.x migrate to Samba-3. Carefully study the chapters that document + the new password backend behavior and the new group mapping functionality. + </para> + <itemizedlist> + <listitem><para>The <parameter>username map</parameter> facility may be needed.</para></listitem> + <listitem><para>Use <command>net groupmap</command> to connect NT4 groups to UNIX groups.</para></listitem> + <listitem><para>Use <command>pdbedit</command> to set/change user configuration.</para> + + <para> + When migrating to LDAP backend, it may be easier to dump the initial + LDAP database to LDIF, edit, then reload into LDAP. + </para> + </listitem> + </itemizedlist> + </listitem> + </varlistentry> + + <varlistentry><term>OS Specific Scripts/Programs may be Needed</term><listitem> + <para> + Every operating system has its peculiarities. These are the result of engineering decisions + that were based on the experience of the designer, and may have side-effects that were not + anticipated. Limitations that may bite the Windows network administrator include: + </para> + <itemizedlist> + <listitem><para>Add/Delete Users: Note OS limits on size of name + (Linux 8 chars) NT4 up to 254 chars.</para></listitem> + <listitem><para>Add/Delete Machines: Applied only to Domain Members + (Note: machine names may be limited to 16 characters).</para></listitem> + <listitem><para>Use <command>net groupmap</command> to connect NT4 groups to UNIX groups.</para></listitem> + <listitem><para>Add/Delete Groups: Note OS limits on size and nature. + Linux limit is 16 char, no spaces and no upper case chars (<command>groupadd</command>).</para></listitem> + </itemizedlist> + </listitem> + </varlistentry> + + <varlistentry><term>Migration Tools</term><listitem> + <para> +<indexterm><primary>pdbedit</primary></indexterm> + Domain Control (NT4 Style) Profiles, Policies, Access Controls, Security + <itemizedlist> + <listitem><para>Samba: <command>net, rpcclient, smbpasswd, pdbedit, profiles.</command></para></listitem> + <listitem><para>Windows: <command>NT4 Domain User Manager, Server Manager (NEXUS)</command></para></listitem> + </itemizedlist> + </para> + </listitem> + </varlistentry> +</variablelist> + +</sect2> + +</sect1> + +</chapter> |