Your company has an Active Directory Domain Services (AD DS) domain. All servers run Windows
Server 2008 R2. All client computers run Windows 7. You virtualize applications by using Microsoft
Application Virtualization (App-V). You are deploying servers to five new branch offices. Each branch
office will stream virtual applications from a local file server and perform application sequencing
locally. You need to replicate application packages to all file servers and minimize bandwidth usage.
What should you do?
A.
Create a Distributed File System (DFS) root on each file server.
B.
On each file server, add the BranchCache for network files role service.
C.
Creates an Active Directory Distributed File System (DFS) root target folder.
D.
Create a Distributed File System Replication (DFSR) full mesh replication group.
Explanation:
Distributed File System Distributed File System (DFS) Namespaces and DFS Replication offer
simplified, highly-available access to files, load sharing, and WAN-friendly replication. In the
Windows Server® 2003 R2 operating system, Microsoft revised and renamed DFS Namespaces
(formerly called DFS), replaced the Distributed File System snap-in with the DFS Management snapin, and introduced
the new DFS Replication feature. In the Windows Server® 2008 operating system, Microsoft added
the Windows Server 2008 mode of domain-based namespaces and added a number of usability and
performance improvements.
What does Distributed File System (DFS) do?
The Distributed File System (DFS) technologies offer wide area network (WAN)-friendly replication as
well as simplified, highly-available access to geographically dispersed files. The two technologies in
DFS are the following:DFS Namespaces. Enables you to group shared folders that are located on different servers into one
or more logically structured namespaces. Each namespace appears to users as a single shared folder
with a series of subfolders. This structure increases availability and automatically connects users to
shared folders in the same Active Directory Domain Services site, when available, instead of routing
them over WAN connections.
DFS Replication. DFS Replication is an efficient, multiple-master replication engine that you can use
to keep folders synchronized between servers across limited bandwidth network connections. It
replaces the File Replication Service (FRS) as the replication engine for DFS Namespaces, as well as
for replicating the AD DS SYSVOL folder in domains that use the Windows Server 2008 domain
functional level. http://technet.microsoft.com/en-us/library/cc753479(WS.10).aspx
BranchCache Key BranchCache design points
While you design your BranchCache solution, it is useful to remember the following key points:
BranchCache can decrease wide area network traffic between computers that are running Windows
Server® 2008 R2 and computers that are running Windows® 7. BranchCache has two modes of
operation, distributed cache mode and hosted cache mode. When the content cache at a branch
office is distributed among client computers, BranchCache is running in distributed cache mode.
When the content cache at a branch office is hosted on a server computer, BranchCache is running
in hosted cache mode. BranchCache is installed by default on client computers running Windows® 7
Enterprise and Windows® 7 Ultimate, however you must enable BranchCache and create firewall
exceptions to allow BranchCache traffic between client computers. BranchCache supports the
optimization of downloads over end-to-end secure transports such as Hypertext Transfer Protocol
Secure (HTTPS) and Internet Protocol security (IPsec). To cache application and Web server content
that is sent to branch offices over Hypertext Transfer Protocol (HTTP), you must install the
BranchCache feature on the application server or Web
server whose content you wish to cache in branch offices. To cache File Server content that is sent to
branch offices using the Server Message Block (SMB) protocol, the BranchCache for network files
role service of the File Server role in Windows Server 2008 R2 must be installed and enabled.
BranchCache might not function correctly when used in combination with a hardware-based WAN
accelerator, because WAN accelerators might alter the fields and messages that are necessary for
BranchCache operation. When you deploy a WAN accelerator with BranchCache, BranchCache might
work for some protocols, but not for other protocols. For example, some WAN accelerators cannot
process server message block (SMB) 2.1, but can process HTTP and HTTPs. Review your WAN
accelerator documentation for more information. BranchCache is designed to prevent unauthorized
access to content. Before transfer between peers or between clients and the hosted cache server,
content is encrypted by BranchCache. Content can only be decrypted using the identifiers provided
by the content server in the main office. The content server provides identifiers only to
authenticated clients that are members of the same domain as the content server. Distributed cache
mode is best suited for small branch offices that do not contain a local server for use as a hosted
cache server. Distributed cache mode allows you to deploy BranchCache with minimal hardware
deployments in branch offices. However, if the branch office contains additional infrastructure, such
as one or more servers that are running other workloads, deploying BranchCache in hosted cache
mode might be beneficial for the following reasons:
Increased cache availability. Hosted Cache mode increases the cache efficiency because content is
available even if the client that originally requested and cached the data is offline. Because the
hosted cache server is always available, more content is cached, providing greater WAN bandwidth
savings, and BranchCache efficiency is improved.
Centralized caching for multiple-subnet branch offices . Distributed cache mode operates on a single
subnet. At a multiple-subnet branch office that is configured for distributed cache mode, a filedownloaded to one subnet cannot be shared with client computers on other subnets. Because of
this, clients on other subnets, unable to discover that the file has already been downloaded, get the
file from the main office content server, using WAN bandwidth in the process. When you deploy
hosted cache mode, however, this is not the case – all clients in a multiple-subnet branch office can
access a single cache, which is stored on the hosted cache server, even if the clients are on different
subnets. If you have a multiple-subnet branch office with less than 100 users, therefore, using
hosted cache mode is recommended. You can use the following guidelines to determine the mode in
which you want to deploy BranchCache: For a branch office that contains less than 100 users and
does not have any local servers, use distributed cache mode. For a branch office (either single
subnet or multiple-subnet) that contains less than 100 users and also contains a local server that you
can use as a hosted cache server, use hosted cache mode. For a multiple-subnet branch office that
contains more than 100 users, but less than 100 users per subnet, use distributed cache mode.
http://technet.microsoft.com/en-au/library/ee307962(WS.10).aspx