DFS研究

1、DFS和杀毒软件的影响：http://www.symantec.com/connect/forums/sep-and-dfs-replication

2、DFS深度：http://technet.microsoft.com/zh-cn/library/cc782417(v=ws.10).aspx

http://msdn.microsoft.com/en-us/library/windows/desktop/dd405482(v=vs.85).aspx

3.

Generally DFS replication is totally depends on AD replication you set at your place.

• Intra-site use KCC replication topology and it takes 15 seconds.
• Inter-site use ISTG and take minimum 15 minutes minimum and maximum depends on the schedule that you configured, default it will be 180(minutes).If you do force replication(using site and services console), it will happen immediately.

Also Requirements for running DFS Management: There are no additional hardware or software requirements for running DFS Management or using DFS Namespaces, except for the newly added features described previously, which require in Windows Server 2012 (or in some cases Windows 8).

Before you can deploy DFS Replication, you must configure your servers as follows:

• Update the Active Directory Domain Services (AD DS) schema to include Windows Server 2012, Windows Server 2008 R2, Windows Server 2008, or Windows Server 2003 R2 schema additions. (If you install a domain controller running Windows Server 2012 the schema is automatically updated.) You cannot use read-only replicated folders with the Windows Server 2003 R2 or older schema additions.
• Ensure that all servers in a replication group are located in the same forest. You cannot enable replication across servers in different forests.
• Install DFS Replication on all servers that will act as members of a replication group.
• Contact your antivirus software vendor to check that your antivirus software is compatible with DFS Replication.
• Locate any folders that you want to replicate on volumes formatted with the NTFS file system. DFS Replication does not support the Resilient File System (ReFS) or the FAT file system.DFS Replication also does not support replicating content stored on Cluster Shared Volumes.

4.

5.

The following list provides a set of scalability guidelines that have been tested by Microsoft on Windows Server 2008 R2 and Windows Server 2008:

• Size of all replicated files on a server: 10 terabytes.
• Number of replicated files on a volume: 8 million.
• Maximum file size: 64 gigabytes.
• Windows 和 DFS 复制支持包含多达 3.2 万个字符的文件夹路径。DFS 复制并不仅限于 260 个字符的文件夹路径。

以下列表提供了一组可伸缩性指南，已由 Microsoft 在 Windows Server 2008 R2 和 Windows Server 2008 上进行了测试：

• 服务器上所有已复制文件的大小：10 TB。
• 卷上所有已复制文件的数量：800 万个。
• 最大文件大小：64 GB。
• 不再限制复制组、已复制文件夹、连接或复制组成员的数量。

6. FAQ

http://technet.microsoft.com/zh-cn/library/cc773238(v=WS.10).aspx

7.

How To - Q2. Why is there a 15 minutes interval limit in DFS-R and bandwidth throttling?

A. This is determined by the way that the operation system stores the information of DFS replication.

The DFS Replication schedule is stored as a binary attribute of size 336 bytes (2*24*7) which represents a schedule for a week. Each hour is represented in two bytes. Every hour is divided into four quarters, each of which occupies four bits, hence the 15 minutes interval:

[...]      [...]       [...]       [...]
0 14   15 29    30 44    45 59

The four bits of a quarter takes 16 value ranges from 0X0, which indicates schedule is OFF, to 0xF, which indicates an ON schedule with full bandwidth. The levels in between defines an ON schedule with different levels of bandwidth.

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Laura Zhang – MSFT

8.http://social.technet.microsoft.com/Forums/windowsserver/en-US/73bbad1a-ee5a-433b-b409-793e0697e7a2/dfs-file-replication-schedule-modification-in-server-2k8