HP Pre-Planning Guide for Windows Server 2012 Clustering Abstract This pre-planning guide provides information about preparing to install the Windows Server 2012 and Windows Server 2012 R2 Operating Systems for use with Microsoft Cluster Server.
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Contents 1 Introduction...............................................................................................4 2 Microsoft Failover Clustering Storage Dependencies........................................5 3 Windows Server 2012 Failover Clustering Behavior.........................................6 Cluster Disk Resources...............................................................................................................6 Cluster Shared Volumes................................................
1 Introduction Microsoft Failover Clustering, formerly known as Microsoft Cluster Server (MSCS), is the clustering solution included in Microsoft Windows Server 2008 and later server operating systems. Microsoft Failover Clustering groups individual systems together to improve availability, scalability, maintainability, and workload management. These benefits improve as the number of cluster nodes is increased.
2 Microsoft Failover Clustering Storage Dependencies HP Storage functionality allows initiator logins and SCSI-3 persistent reservations. These mechanisms are used to facilitate clustering functions such as: • Cluster membership • I/O fencing • Disk resources state change (online/offline) • Disk failover and arbitration Services such as file shares and virtual machines can be housed on external storage arrays. Only one cluster node at a time will provide these services.
3 Windows Server 2012 Failover Clustering Behavior Microsoft Failover Clustering exclusively uses SCSI-3 Persistent Reservations. Microsoft Failover Clustering generates a single unique reservation key per cluster node; the key is used for all LUNs managed by the cluster. Prior to bringing a disk resource online and reserving the associated logical unit (LUN), an initiator must register its reservation key with the LUN.
Cluster Shared Volumes Clustering shared volumes allows multiple cluster nodes to access a LUN simultaneously. In this case, Microsoft Failover Clustering requires each cluster node to register each logical path to the LUN. Each cluster node uses a unique key to register its paths. For example, if there are four cluster nodes with two logical paths each, eight keys are registered for that LUN.
4 Considerations when Planning Failover Clusters There are many factors to consider when building large-scale clusters with Windows Server 2012. It is important to understand the capabilities of the storage array and how those capabilities may influence the implementation of the cluster. The following sections discuss important factors and capabilities that must be considered when planning a large failover cluster using Windows Server 2012.
The Number of Paths per Cluster Node Microsoft Failover Clustering may send multiple registrations to a LUN, depending on the resource type, number of paths, and number of hosts. Due to this behavior, the maximum number of paths configured to a LUN is directly related to the number of registrations supported per LUN or port. Clustering disk resources will reserve exclusive access to the LUN and will register only the paths of the owning node.
The Number of LUNs Managed by the Cluster Microsoft Failover Clustering sends a single reservation per LUN. Due to this behavior, the maximum number of LUNs managed by the cluster is directly related to the number of reservations supported per port or array.
5 Calculating the Supported Scale of a Failover Cluster All storage arrays have quantifiable capabilities in regards to the number of nodes in a cluster, initiator logins, registrations, and reservations that can be managed by the array. These capabilities must be considered when deciding the number of nodes that will be in a cluster, the number of paths per cluster node, and the number of target ports to utilize in the configuration.
6 Example: 64-Node Cluster with HP 3PAR StoreServ 10000 1. Use the following formula to calculate the maximum number of paths per host: 2. Use the following formula to calculate the minimum number of target ports: 3. Make sure that all requirements have been met.
NOTE: • The requirement to have less than or equal to two paths is achieved by zoning each initiator port with a different target port. • The requirement to use two or more target ports is achieved by zoning the first 32 cluster nodes to a pair of ports and the second 32 nodes to a different pair of ports. This effectively spreads the initiator logins across four target ports.
7 Support and Other Resources Contacting HP For worldwide technical support information, see the HP support website: http://www.hp.
For information about: See: Migrating data from one HP 3PAR storage system to another HP 3PAR-to-3PAR Storage Peer Motion Guide Configuring the Secure Service Custodian server in order to monitor and control HP 3PAR storage systems HP 3PAR Secure Service Custodian Configuration Utility Reference Using the CLI to configure and manage HP 3PAR Remote Copy HP 3PAR Remote Copy Software User’s Guide Updating HP 3PAR operating systems HP 3PAR Upgrade Pre-Planning Guide Identifying storage system components
For information about: See: Planning for HP 3PAR storage system setup Hardware specifications, installation considerations, power requirements, networking options, and cabling information for HP 3PAR storage systems HP 3PAR 7200, 7400, and 7450 storage systems HP 3PAR StoreServ 7000 Storage Site Planning Manual HP 3PAR StoreServ 7450 Storage Site Planning Manual HP 3PAR 10000 storage systems HP 3PAR StoreServ 10000 Storage Physical Planning Manual HP 3PAR StoreServ 10000 Storage Third-Party Rack Physic
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