13 things your company needs to know about DFS replication
In this article you will understand more about DFS replication and 13 important things that your company and IT professionals should be aware of when using this replication solution. Check it out below.
What is DFS replication
DFS replication is an important online technology, part of digital transformation , that allows companies to store data more efficiently and securely.
This service allows your business to store files and folders on more than one file server.
When changes are made to these files and folders on one of the servers, they are automatically replicated to the configured replication groups.
The DFS replication feature is a feature in Windows Server that helps keep all folders synchronized across network connections, and works equally well on wireless networks.
This function replaces the File Replication Service (FRS) in the DFS namespace replication engine.
It still replicates the Active Directory Domain Services (AD DS) SYSVOL folder in domains that use the Windows Server 2008 or newer functional level.
DFS Replication uses a compression algorithm called RDC (Remote Differential Compression). Understand below its importance in this role.
1. RDC in DFS replication
RDC (Remote Differential Compression) is a type of algorithm that acts as a protocol between client and server and has the function of updating your files efficiently when using networks with limited bandwidth.
RDC is capable of detecting insertions, removals and reorganizations of data present in stored files.
This allows DFS Replication to replicate only the changes made, not the entire file, which creates efficiency for larger file or folder sizes.
However, be aware that RDC is only used on files of 64 KB or more.
It is important to consider this detail because important data contained in files outside this parameter may be lost.
2. When not to use DFS replication
This function should not be used in network environments where several users modify the same files simultaneously on different servers.
This can cause DFS replication to move conflicting copies of your files to a hidden deleted items folder (Dfsr Private\Conflict and Deleted).
In cases where multiple users need to make updates at the same time, it is recommended to use the File Checkout feature in Windows SharePoint Services, which ensures that only one user works on a file at a time.
Check if your Windows Server has the Windows SharePoint Services 2.0 role, as it is generally not included in newer versions.
3. Requirements for Using DFS Replication
The main requirement is to correctly configure your servers before activating this function. Check below how this should be done.
First, update your Active Directory Domain Services (ADDS) schema to include schemas from Windows Server 2003 R2 or newer.
Check that your servers included in the replication group are located in the same tree, as it is not possible to enable replication if they are in different “forests”.
Then, install DFS Replication on all servers that will be part of this replication group to guarantee that the service runs properly.
Check if your antivirus software is compatible with this function, to ensure effectiveness in protecting your data. This detail is very important to avoid invasions and damage to your business.
Select the folders you want to replicate and ensure they are formatted in the NTFS file system, as the DFS Replication function does not support files in the ReFS or FAT format.
Furthermore, this function does not support content stored on shared volumes that are clustered.
4. Understand your server’s system resource consumption
Your server’s resource consumption depends on several factors such as your disk, memory and CPU resources used, which includes the number and size of files and folders, their rate of change and the number of replication group members .
Furthermore, other resources such as ESE Technology are also difficult to estimate and must be considered on a case-by-case basis.
If you use this technology, be aware that it can consume a large part of the available memory, usually freed on demand.
Consult your providers to find out more details about the resource consumption of each service used to avoid overload problems and integration errors.
5. Authorization level to be able to replicate files
Because DFS Replication is a service that works through your account on the local system, you do not need to log in as an administrator, for example, to be able to replicate updates.
However, you must be a domain administrator or local administrator of the file servers to be able to change DFS Replication settings.
6. How DFS Replication Frequency Works
Updates made to files and folders are replicated according to the schedule you set. It can be done according to your desires and needs.
It has great flexibility, which allows scheduling to be configured every 10 minutes, days or weeks.
Furthermore, replication is enabled between these intervals, starting after detecting any file changes, generally happening within seconds.
When you want to schedule a timeout in the replication group, do so according to the local time of the member hosting the incoming connection.
Then, scheduling takes place according to the local time of other members when considering multiple time zones.
7. Possibility to replicate more than one folder on a server
DFS replication allows multiple folders to be replicated between different servers, which creates efficiency in the development of data transfers.
However, it is important that you verify that the replicated folders have a unique root path so that they do not overlap.
8. DFS replication in Mixed environments (Windows/UNIX)
Although DFS Replication is supported only between servers running Windows Server, clients using UNIX can access shares on Windows servers.
For this to be possible, you must configure NFS services on the DFS Replication server, otherwise it is not possible to integrate the function.
You can use the functionality of SMB/CIFS clients that are included with UNIX to access directly from Windows, although this is limited or requires changes to the Windows environment.
9. File System Policies Affect DFS Replication
To ensure that DFS replication happens correctly, you should not configure system policies on the replicated folders.
The file system policy reapplies NTFS rights at Group Policy refresh intervals, resulting in sharing violations because open files are not duplicated until they are closed.
10. Using DFS replication on offline files
It is perfectly possible to use DFS replication on offline files in situations where only one user at a time makes changes to files.
However, do not use DFS replication with offline files in environments with multiple concurrent users, as there is no distributed locking mechanism or file checkout function.
If two users modify the same file on different servers at the same time, DFS replication moves the older file to a hidden folder in its source path.
11. DFS replication does not communicate with FRS
Even though they can be run at the same time, DFS replication does not communicate with FRS.
Roles should never be configured to replicate the same folders or subfolders at the same time to avoid data loss.
12. Time synchronization between servers
DFS replication generally does not require time synchronization between servers, but it is important to check with your service provider or the settings used on the servers.
However, it requires that server times be configured within five minutes of each other for Kerberos network protocol authentication to work correctly.
13. When a WAN link fails during replication
If this happens, such as in cases where the connection is disabled, DFS Replication will continue trying to replicate the updates until the connection is restored.
It is possible to collect connectivity error information in the DFS Replication event log using MOM, which, through automatic alerts, warns of a possible failure.