Step-by-Step Guide for Configuring a Two-Node File Server Failover Cluster in Windows Server 2008
Servers in a failover cluster can function in a variety of
roles, including the roles of file server, print server, mail server, or
database server, and they can provide high availability for a variety of other
services and applications. This guide describes how to configure a two-node
file server cluster.
A failover cluster usually includes a storage unit that is
physically connected to all the servers in the cluster, although any given
volume in the storage is only accessed by one server at a time. The following
diagram shows a two-node failover cluster connected to a storage unit.
Failover cluster with two nodes connected to a storage unit
Storage volumes or logical unit numbers (LUNs) exposed to
the nodes in a cluster must not be exposed to other servers, including servers
in another cluster. The following diagram illustrates this.
Two failover clusters, each with its own LUNs
Note that for the maximum availability of any server, it is
important to follow best practices for server management—for example, carefully
managing the physical environment of the servers, testing software changes
before fully implementing them, and carefully keeping track of software updates
and configuration changes on all clustered servers.
The following scenario describes how a file server failover
cluster can be configured. The files being shared are on the cluster storage,
and either clustered server can act as the file server that shares them.
Shared folders in a failover cluster
In Windows Server 2008, the interfaces for viewing or
configuring shared folders in a failover cluster have been extended and
streamlined. Configuration is more straightforward and misconfiguration is less
likely. The following list describes functionality that is integrated into
failover clustering:
- Display is scoped to clustered shared folders only (no mixing with nonclustered shared folders): When you or a user views shared folders by specifying the path of a clustered file server, the display will include only the shared folders that are part of the cluster. It will exclude nonclustered shared folders that happen to be on a node of the cluster.
- Access-based enumeration: You can use access-based enumeration to hide a specified folder from users' view. Instead of allowing users to see the folder but not access anything on it, you can choose to prevent them from seeing the folder at all. You can configure access-based enumeration for a clustered shared folder in the same way as for a nonclustered shared folder.
- Offline access: You can configure offline access (caching) for a clustered shared folder in the same way as for a nonclustered shared folder.
- Clustered disks are always recognized as part of the cluster: Whether you use the failover cluster interface, Windows Explorer, or the Share and Storage Management snap-in, Windows Server 2008 recognizes whether a disk has been designated as being in the cluster storage. If such a disk has already been configured in Failover Cluster Management as part of a clustered file server, you can then use any of the previously-mentioned interfaces to create a share on the disk. If such a disk has not been configured as part of a clustered file server, you cannot mistakenly create a share on it. Instead, an error indicates that the disk must first be configured as part of a clustered file server before it can be shared.
- Integration of Services for Network File System: The File Server role in Windows Server 2008 includes the optional role service called Services for Network File System (NFS). By installing the role service and configuring shared folders with Services for NFS, you can create a clustered file server that supports UNIX-based clients.
Requirements for a two-node failover cluster
To create a failover cluster with two nodes (regardless of
the service or application that the nodes provide), you need the hardware,
software, accounts, and network infrastructure described in the sections that
follow.
We recommend that you first use the information provided in
this guide in a test lab environment. A Step-by-Step guide is not necessarily
meant to be used to deploy Windows Server features without the accompanying
documentation (as listed in the Additional references section), and it should
be used with discretion as a stand-alone document.
Hardware requirements for a two-node failover cluster
You will need the following hardware for a two-node failover
cluster:
· Servers: We recommend that you use a set of matching
computers that contain the same or similar components.
· Network adapters and cable (for network communication):
The network hardware, like other components in the failover cluster solution,
must be compatible with Windows Server 2008. If you use iSCSI, your
network adapters must be dedicated to either network communication or iSCSI,
not both.
In the network infrastructure that connects your cluster
nodes, avoid having single points of failure. There are multiple ways of
accomplishing this. You can connect your cluster nodes by multiple, distinct
networks. Alternatively, you can connect your cluster nodes with one network
that is constructed with teamed network adapters, redundant switches, redundant
routers, or similar hardware that removes single points of failure.
Note
If you connect cluster nodes with a single network,
the network will pass the redundancy requirement in the Validate a
Configuration Wizard. However, the report from the wizard will include a
warning that the network should not have single points of failure.
Device controllers or
appropriate adapters for the storage:
- For Serial Attached SCSI or Fibre Channel: If you are using Serial Attached SCSI or Fibre Channel, in all clustered servers, the mass-storage device controllers that are dedicated to the cluster storage should be identical. They should also use the same firmware version.
- For iSCSI: If you are using iSCSI, each clustered server must have one or more network adapters or host bus adapters that are dedicated to the cluster storage. The network you use for iSCSI cannot be used for network communication. In all clustered servers, the network adapters you use to connect to the iSCSI storage target should be identical, and we recommend that you use Gigabit Ethernet or higher.
For iSCSI, you cannot use teamed network adapters, because
they are not supported with iSCSI.
- Storage: You must use shared storage that is compatible with Windows Server 2008.
For a two-node failover cluster, the storage should
contain at least two separate volumes (LUNs), configured at the hardware level.
One volume will function as the witness disk (described in the next paragraph).
One volume will contain the files that are being shared to users. Storage
requirements include the following:
- To use the native disk support included in failover clustering, use basic disks, not dynamic disks.
- We recommend that you format the partitions with NTFS (for the witness disk, the partition must be NTFS).
- For the partition style of the disk, you can use either master boot record (MBR) or GUID partition table (GPT).
The witness disk is a disk in the cluster storage that is
designated to hold a copy of the cluster configuration database. (A witness
disk is part of some, not all, quorum configurations.) For this two-node
cluster, the quorum configuration will be Node and Disk Majority,
the default for a cluster with an even number of nodes. Node and
Disk Majority means that the nodes and the witness disk each contain
copies of the cluster configuration, and the cluster has quorum as long as a
majority (two out of three) of these copies are available.
Deploying storage area networks with failover clusters
When deploying a storage area network (SAN) with a failover
cluster, follow these guidelines:
- Confirm compatibility of the storage: Confirm with manufacturers and vendors that the storage, including drivers, firmware, and software used for the storage, are compatible with failover clusters in Windows Server 2008.
- Because improvements in failover clusters require that the storage respond correctly to specific SCSI commands, the storage must follow the standard called SCSI Primary Commands-3 (SPC-3). In particular, the storage must support Persistent Reservations as specified in the SPC-3 standard.
- The miniport driver used for the storage must work with the Microsoft Storport storage driver.
· Isolate storage devices, one cluster per device:
Servers from different clusters must not be able to access the same storage
devices. In most cases, a LUN that is used for one set of cluster servers
should be isolated from all other servers through LUN masking or zoning.
· Consider using multipath I/O software: In a highly
available storage fabric, you can deploy failover clusters with multiple host
bus adapters by using multipath I/O software. This provides the highest level
of redundancy and availability. For Windows Server 2008, your multipath
solution must be based on Microsoft Multipath I/O (MPIO). Your hardware vendor
will usually supply an MPIO device-specific module (DSM) for your hardware,
although Windows Server 2008 includes one or more DSMs as part of the
operating system.
Software requirements for a two-node failover cluster
The servers for a two-node failover cluster must run the
same version of Windows Server 2008, including the same hardware version
(32-bit, x64-based, or Itanium architecture-based). They should also have the
same software updates (patches) and service packs.
Network infrastructure and domain account requirements for a two-node failover cluster
You will need the following network infrastructure for a
two-node failover cluster and an administrative account with the following
domain permissions:
- Network settings and IP addresses: When you use identical network adapters for a network, also use identical communication settings on those adapters (for example, Speed, Duplex Mode, Flow Control, and Media Type). Also, compare the settings between the network adapter and the switch it connects to and make sure that no settings are in conflict.
- If you have private networks that are not routed to the rest of your network infrastructure, ensure that each of these private networks uses a unique subnet. This is necessary even if you give each network adapter a unique IP address. For example, if you have a cluster node in a central office that uses one physical network, and another node in a branch office that uses a separate physical network, do not specify 10.0.0.0/24 for both networks, even if you give each adapter a unique IP address.
- DNS: The servers in the cluster must be using Domain Name System (DNS) for name resolution. The DNS dynamic update protocol can be used.
- Domain role: All servers in the cluster must be in the same Active Directory domain. As a best practice, all clustered servers should have the same domain role (either member server or domain controller). The recommended role is member server.
- Domain controller: We recommend that your clustered servers be member servers. If they are, you need an additional server that acts as the domain controller in the domain that contains your failover cluster.
- Clients: As needed for testing, you can connect one or more networked clients to the failover cluster that you create, and observe the effect on a client when you move or fail over the clustered file server from one cluster node to the other.
- Account for administering the cluster: When you first create a cluster or add servers to it, you must be logged on to the domain with an account that has administrator rights and permissions on all servers in that cluster. The account does not need to be a Domain Admins account, but can be a Domain Users account that is in the Administrators group on each clustered server. In addition, if the account is not a Domain Admins account, the account (or the group that the account is a member of) must be given the Create Computer Objects permission in the domain.
You must complete the following steps to install a two-node
file server failover cluster.
Step 1: Connect the cluster
servers to the networks and storage
Step 2: Install the failover cluster feature
Step 3: Validate the cluster configuration
Step 4: Create the cluster
If you have already installed the cluster nodes and want to
configure a file server failover cluster,
Step 1: Connect the cluster servers to the networks and storage
Use the following instructions to connect your selected
cluster servers to networks and storage.
Review Hardware Requirements for a
Two-Node Failover Cluster earlier in this
guide, for details about the kinds of network adapters and device controllers
that you can use with Windows Server 2008.
For a failover cluster network, avoid having single points
of failure. There are multiple ways of accomplishing this. You can connect your
cluster nodes by multiple, distinct networks. Alternatively, you can connect
your cluster nodes with one network that is constructed with teamed network
adapters, redundant switches, redundant routers, or similar hardware that
removes single points of failure (If you use a network for iSCSI, you must
create this network in addition to the other networks).
For a two-node file server cluster, when you connect the
servers to the cluster storage, you must expose at least two volumes (LUNs).
You can expose additional volumes as needed for thorough testing of your
configuration. Do not expose the clustered volumes to servers that are not in
the cluster.
To connect the cluster servers to
the networks and storage
1. Review the details about networks in Hardware Requirements for a
Two-Node Failover Cluster and Network infrastructure and
domain account requirements for a two-node failover cluster,
earlier in this guide.
2. Connect and configure the networks that the
servers in the cluster will use.
3. If your test configuration includes clients
or a non-clustered domain controller, make sure that these computers can
connect to the clustered servers through at least one network.
4. Follow the manufacturer's instructions for
physically connecting the servers to the storage.
5. Ensure that the disks (LUNs) that you want
to use in the cluster are exposed to the servers that you will cluster (and
only those servers). You can use any of the following interfaces to expose
disks or LUNs:
6. If you have purchased software that
controls the format or function of the disk, follow instructions from the
vendor about how to use that software with Windows Server 2008.
7. On one of the servers that you want to
cluster, click Start, click Administrative
Tools, click Computer Management, and then click
Disk Management. (If the User Account
Control dialog box appears, confirm that the action it displays is
what you want, and then click Continue.) In Disk
Management, confirm that the cluster disks are visible.
8. If you want to have a storage volume larger
than 2 terabytes, and you are using the Windows interface to control the
format of the disk, convert that disk to the partition style called GUID
partition table (GPT). To do this, back up any data on the disk, delete all
volumes on the disk and then, in Disk Management, right-click the disk (not a
partition) and click Convert to GPT Disk.
For volumes smaller than 2 terabytes, instead of using
GPT, you can use the partition style called master boot record (MBR).
You can use either MBR or GPT for a disk that is used by a
failover cluster, but you cannot use a disk that you converted to dynamic by
using Disk Management.
If you purchased software that controls the format or
function of the disk, contact the vendor for instructions about how to use
that software with Windows Server 2008.
9. Check the format of any exposed volume or
LUN. We recommend NTFS for the format (for the witness disk, you must use
NTFS).
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Step 2: Install the failover cluster feature
In this step, you install the failover cluster feature. The
servers must be running Windows Server 2008.
To install the failover cluster
feature on the servers
1. If you recently installed Windows
Server 2008, the Initial Configuration Tasks
interface is displayed, as shown in the following illustration.
Initial Configuration Tasks
If this interface is displayed, under Customize
This Server, click Add features. Then skip to step 3.
Server Manager
In Server Manager, under Features Summary, click Add Features.
3. In the Add Features Wizard,
click Failover Clustering, and then click Install.
4. Follow the instructions in the wizard to
complete the installation of the feature. When the wizard finishes, close it.
5. Repeat the process for each server that
you want to include in the cluster.
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