Module 16: Implementing Directory
Replication
- The Briefcase can note whether either copy of the file has
changed, and then updates the unchanged copy. If both copies of the file have changed,
Briefcase notes this, but does not automatically update the copies unless the application
that created the file supports the Briefcase merge feature, such as MS Access 7.0 or
above. You can then choose which, if either, file to replace.
- The Briefcase Database stores the information required by NT to
synchronize files. Briefcase Database is located at
\systemroot\Profiles\user_name\Desktop\My Briefcase. These files are only available from
the command prompt, not Explorer
- Three steps are involved in using Briefcase.
- Copying files to the Briefcase using any copy method. Files never
get moved to the Briefcase; they are always copied to the Briefcase.
- Working on Files in the Briefcase.
- Synchronizing Updated Files. Using Briefcase-->Update.
There are four options.
- Replace. One copy has been updated, but not both.
- Skip. Both copies have been updated.
- Delete. One copy has been deleted. Update result will be the other
copy also deleted. I tried this. This is definitely not a good design. How about somebody
accidentally deleted one copy.
- Merge. Both copies have been updated and the application that
created the file support merge.
- Microsoft Windows NT uses Directory
Replicator service (can also be setup on NT Workstation):
- To maintain identical folder hierarchies,
which can include logon scripts, system policy files and other commonly used files on
multiple servers.
- Allows users to access multiple servers for
user account information (balancing).
Types of Data Maintained by
Directory Replication |
Directory replication can be used to maintain any type of data.
The commonly replicated data are:
Logon Scripts
- Logon scripts are batch files, command files, or executable
programs that can be assigned to user accounts.
- Each time a user logs on, the assigned logon script is run. Then a
server processes a logon request, the system locates the logon script by combining a file
name specified in User Manager for Domains with a path specified in Server Manager.
System Policy Files
- System policy files are used to control the user's work
environment and implement uniform system configurations for all computers in an
organization.
Commonly used Information.
- Replicating files to several servers allows you to setup load
balancing.
These files are usually marked as read-only, because they typically
contain information that is needed by many users, but should not be modified by those
users.
Directory Replication
Components |
- Export Server --> replicate
updated directories from a designated master directory to a designated directory on import
computers. Can only be Windows NT Server computer.
- Import Computer --> receive
updates of replicated directories. Following possibilities:
- Windows NT Server or Workstation
- Microsoft LAN Manager for OS/2 servers
Export and Import
Directories |
- Master Export Directory
- By default, master export directory is System32\Repl\Export.
- System32\Repl\Export is shared as Repl$ when Directory
Replicator service is started.
- In order for replication to occur, files must be placed in
subdirectories in the System32\Repl\Export directory. Any files placed directly in the
System32\Repl\Export directory will not be replicated.
- Import Directory
- Be default, import directory is System32\Repl\import.
- The Directory Replicator service automatically creates
subdirectories under this directory to match those on the export directory.
You use Server Manager to manage or change the default export
or import directory paths.
The Directory Replication
Process |
- After the files and directories have been set up for directory
replication, the Directory Replicator services control the replication process.
- The export server periodically checks the export directory for
changes. The timing for checking replicated directories is set by the Interval parameter.
- If any changes have occurred, the following process will occur.
- The export server sends update notices to the import computers or
domains.
- When an import computer receives an update notice, it calls the
export server and reads the export directory structure.
- The import computer copies any new or changed files to its import
directory structure, and deletes any of the import files that are no longer in the export
directory structure.
The parameters that control Directory Replicator Service are
located in: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Replicator\Parameters.
Preparing an Export Server |
- In User Manager for Domains, create a user
account (such as Repl) for the Directory Replicator service to use. Following
specifications:
- All logon hours allowed
- Member of Backup Operators and Replicator
groups for the domain
- Clear check box: User Must Change
Password At Next Logon
- Select check box: Password Never Expires
- From Server Manager (or Services
program in Control Panel) configure the Directory Replicator to start automatically and to
log on as the Replicator user account.
- Create: systemroot\System32\Repl\Export
and place directories with files in it.
- From Server Manager, configure the export
server to export files to other computers or domains.
- TRY THIS OUT!
Note:
If export directory is on NTFS, Replicator
group on export server should have Full Control for export directory tree.
Export server can also be an import
computer |
Preparing an Import Computer |
- If it is not part of domain for export
server or trusting domain, create Replicator user account by using User Manager for
Domains. Specifications:
- Same name and password as account used to
configure the export server, because account must have permission to access the REPL$
share on export server.
- Grant the Replicator user account
membership in the local Replicator group
- From Server Manager (or Services
program) configure the Directory Replicator to start automatically and to log on as the
Replicator user account.
- From Server Manager, configure the
import computers to receive files from other servers or domains.
Managing Directory
Replication |
- When you configure Export server, if the To List is blank, this
export server will replicate to any computer in the same domain configured as an import
computer.
- When you configure Import server, if the From List is blank, this
Import server will receive replicated data from any export server in the same domain.
When you add list to the To List or From List, you
just need to add the server name not the directory.
Managing Replication from an
Export Server |
Server Manager is used to configure a
server as an export server, to specify to which computers to export, and to manage
directories to be exported.
Option |
Description |
From Path |
Path from which
directories are exported |
To List |
Computers or
domains to which directories can be exported. If it is blank it will be exported to any
import computer in same domain |
Locks |
Prevents a
directory from being exported |
Stabilize |
Whether all
files in directory must be stable for specified time after changes before any files are
exported |
Subtree |
Whether entire
subtree is exported |
Locked Since |
Date and time a
lock was placed on directory |
Registry contains entries that control
various aspects of replication. Location:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Replicator\Parameters
There are two entries that are not
configurable by Server Manager. They may have to be added to the Registry to better manage
replication:
- Interval-REG_DWORD:
- how often export server
checks replicated directories for changes.
- Range is 1-60 minutes; default = 5
- GuardTime-REG_DWORD:
- number of minutes an export directory must
be stable (no changes to any files. Range is 0 to one half of the Interval minutes;
default = 2
Managing Replication to an
Import Computer |
Use Server Manager to
manage replication to the import computer. Double-click on the the server name and the Properties
for XXXX server dialog box appears.
Click the Replication
button
Option |
Description |
To Path |
Path in which
replicated directories are stored |
From List |
Servers or
domains that can export to this computer; blank means from any export server |
Locks |
Prevents
directory from being imported |
Status |
Status on
receiving updates from export server:
- OK: directory regularly receives
updates from export server; imported is identical to exported data
- No Master: directory does not
receive updates from export server; may not be running or have stopped exporting
- NoSync: directory has received
updates, but is not current; may be communication failure, open files on export server or
import computer
- [blank]: replication never occurred for the
directory; one or both may not be configure properly
|
Last Update |
Date and time of
last update |
Replication Troubleshooting
Overview |
Error |
Possible Solution |
Access denied |
Use Server
Manager:
- Make sure that the Directory Replicator service is configured to
log on using a specific account.
- Make sure that the account used by the import computer's Directory
Replicator service has permission to read the files on the export server. The default
permissions for an export directory grant Full Control to the Replicator local group. It
this default permission is removed from the directory, exported files are copied to the
import computers but receive the wrong permissions, error message will be recorded. Then
click Permissions on the export directory's Sharing tab and grant Full
Control to the Replicator local group for the export directories.
|
Exporting to
Specific computers |
Be sure to
specify correct export servers and import computers in From List and To List,
respectively in Directory Replication dialog box of Server Manager or Server
program. If they are not specified export from all export servers to all import computers
in local domain |
Replication
to a domain name over a WAN Link |
In Server
Manager, in export To List and import From List, specify computer names
in addition to the domain name |
Logon scripts
are not working |
On non-domain controller computers
running NTS or NTW, store the logon scripts in the following local directory:
\system32\Repl\Import\Scripts |
Some Files Replicated but Others were not |
In order for replication to occur, files must
be placed in subdirectories in the System32\Repl\Export
directory. Any files placed directly in the
System32\Repl\Export directory will not
be replicated |
|