TOOLS (HIT) KIT 3.4.1/3.4.2 — - Dell

DELL EQUALLOGIC HOST INTEGRATION
TOOLS (HIT) KIT 3.4.1/3.4.2 —
NEW FEATURES TO ENHANCE MICROSOFT®
FAILOVER CLUSTERING SUPPORT
A Dell Technical White Paper
High Availability Clustering Solutions
Dell Product Group
Nam Nguyen
October 2010

EqualLogic HIT Kit 3.4.1/3.4.2 — New Features to Enhance Microsoft Failover Clustering Support
Executive Summary
EqualLogic PS-Series arrays are ideal for use as the shared storage system in the Failover Cluster
configuration. PS-Series arrays provide high availability, scalability and manageability. The EqualLogic
Host Integration Tools (HIT) Kit is a comprehensive collection of tools/components to facilitate
deployment and enhance performance of standalone as well as clustered servers. This paper discusses
2 new enhancements being introduced with HIT Kit 3.4.1/3.4.2 for Microsoft Failover Clustering:
Clustered Shared Volume Support and Dynamic Allocation of iSCSI Connections so that users running
Dell Failover Cluster with EqualLogic PS-Series understand better how these features can help them.
THIS WHITE PAPER IS FOR INFORMATIONAL PURPOSES ONLY, AND MAY CONTAIN TYPOGRAPHICAL
ERRORS AND TECHNICAL INACCURACIES. THE CONTENT IS PROVIDED AS IS, WITHOUT EXPRESS OR
IMPLIED WARRANTIES OF ANY KIND.
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October 2010
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EqualLogic HIT Kit 3.4.1/3.4.2 — New Features to Enhance Microsoft Failover Clustering Support
Contents
Executive Summary ....................................................................................................... ii
Introduction ................................................................................................................ 2
EqualLogic Host Integration Tools (HIT) Kit........................................................................... 2
New Features in HIT Kit 3.4.1/3.4.2 ................................................................................... 3
Clustered Shared Volume (CSV) Support .............................................................................. 4
Dynamic Allocation of iSCSI Connections .............................................................................. 4
Information on Dell Failover Cluster Solutions ....................................................................... 5
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EqualLogic HIT Kit 3.4.1/3.4.2 — New Features to Enhance Microsoft Failover Clustering Support
Introduction
A failover cluster is a group of systems that collaborates to run a common set of applications, but
presents itself as a single logical system to client applications. The systems (or nodes) in the cluster are
physically connected either by a local area network (LAN) or a wide area network (WAN), and are
configured with Microsoft® Windows Server® 2008 R2 Failover Clustering software.
Failover clusters are well suited to mission-critical applications that require high availability and
scalability, such as order processing and tracking, inventory control, e-commerce, databases,
messaging systems, file and print services, and virtualized workloads. They help reduce downtime
associated with planned and unplanned events by removing any single point of failure within the
configuration that can cause clustered applications or services to become unavailable. If a hardware or
software component failure causes a service failure, the cluster automatically restarts the failed
service on a functional cluster node, ensuring that no data is lost and that there is minimal disruption
to end users. Once the problem is corrected, services can be automatically balanced by cluster
software or manually balanced by the administrator across all functional nodes.
Dell EqualLogic PS-Series arrays are ideal to use as the shared storage system in a failover cluster
configuration, because they provide high availability, scalability, and manageability.
• High Availability Features: Hot-swappable fans and power supplies, redundant storage
controllers, RAID, hot-spare disk, redundant paths to the storage system, online storage
firmware update, snapshot and replication capabilities
• Scalability Features: Tie-storage system, peer architecture, on-demand volume expansion, and
auto-rebalancing
• Manageability: Easy to install and use, thin provisioning, virtualization support, self-managed,
and comprehensive monitoring and deployment tools
EqualLogic Host Integration Tools (HIT) Kit
The EqualLogic HIT Kit includes:
• Remote Setup Wizard (RSW) — Quickly and easily initialize PS Series storage arrays, set up and
configure access to a PS Series group, and configure multipath I/O on Windows Server 2003,
Windows Server 2008, and Windows Server 2008 R2 operating systems.
• Multipath I/O Device Specific Module (DSM) — Configure multiple redundant network paths
between a system running the Windows® operating system and PS Series group volumes for
high availability and high performance.
• EqualLogic Host Connection Manager (EHCM) – A user mode service that periodically retrieves
the current table from the PS Series Group, monitors iSCSI sessions and SAN topology, and
reconfigures iSCSI session mesh when necessary.
• Auto-Snapshot Manager/Microsoft Edition (ASM/ME) — A Microsoft Volume Shadow Copy (or
Snapshot) Service (VSS) requestor that makes application-consistent smart copies of volumes.
Creates snapshots, clones, and replicas to provide point-in-time protection of critical data for
supported applications, including Microsoft SQL Server®, Exchange Server, Hyper-V, and NTFS
file shares.
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EqualLogic HIT Kit 3.4.1/3.4.2 — New Features to Enhance Microsoft Failover Clustering Support
• VSS Provider — Use VSS to create and manage volume snapshots and replicas in a PS Series
group.
• VDS Provider — Use the Microsoft Virtual Disk Service (VDS) and Microsoft Storage Manager for
SANs to create and manage volumes in a PS Series group.
• Microsoft iSCSI Software Initiator — Include the iSCSI port driver, Initiator Service, and
Software Initiator to help connect to iSCSI devices via the Windows TCP/IP stack using NICs.
• Java Runtime Environment Update — Install necessary Java Runtime Environment (JRE)
updates for the Group Manager graphical user interface (GUI).
New Features in HIT Kit 3.4.1/3.4.2
HIT Kit version 3.4.1/3.4.2 includes the following enhancements and changes:
• Microsoft Exchange Enhancements
o Support for Exchange Server 2010 and 2010 SP1 (HIT 3.4.2)
o LCR and SCR support for Exchange Server 2007
o Support Restore as New for Exchange
• Support for SQL Server 2008 R2 (HIT 3.4.2)
• New PS Series firmware version 5.0 support
o Support for thin clones and template volumes
o SAN data copy offload features
• Support for HPC iSCSI provider
• Remote setup for command-line interface (CLI)
• iSCSI provider for Windows HPC Server
• Offline smart copies
• Support for cloning replicas
• Bulk operations support
• Improvements for Multi-Path I/O (MPIO)
• ASMCLI enhancements
• Simplified trace logging
• Enhancements in Microsoft failover clustering
o Clustered shared volume (CSV) support
o Dynamic allocation of iSCSI connections
These new features and enhancements are well documented in the Host Integration Tools for Microsoft
Windows version 3.4.1/3.4.2 Release Notes. This paper focuses on two specific enhancements in
Microsoft failover clustering: CSV support and dynamic allocation of iSCSI connections.
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EqualLogic HIT Kit 3.4.1/3.4.2 — New Features to Enhance Microsoft Failover Clustering Support
Clustered Shared Volume (CSV) Support
CSV is a new failover clustering feature in Windows Server 2008 R2 that allows concurrent access to a
shared disk by multiple cluster nodes. When used with Hyper-V, CSV provides the following benefits:
• Implements transparency regarding which node owns each volume.
• Uses disk space required for Virtual Machines (VMs) more efficiently by placing multiple Virtual
Hard Disks (VHDs) on a single CSV volume.
• Reduces the time and chance of disconnection for VMs during Live Migration, since the cluster
disk does not have to be taken offline on one node and brought online on another.
• Provides consistent and single namespace.
• Makes the VM the smallest unit for failover, so that the physical disk and all cluster resources
in a group do not failover together
The Auto-Snapshot Manager supports the following operations for CSV environments:
• Smart copy and smart copy schedule creation for any VM on a CSV
• Selective restore of VMs on CSVs
• Moving the coordination node to the local/current node
The following constraints apply to Auto-Snapshot Manager support for CSVs:
• In a CSV-enabled failover cluster, you cannot create a Smart Copy (or a Smart Copy Schedule)
for a CSV from any node, including the coordination node.
• You cannot add a CSV or any VMs that reside on a CSV to a collection.
• ASM/ME does not permit in-place restores of CSVs, because every copy of a CSV is a torn smart
copy.
Dynamic Allocation of iSCSI Connections
EHCM monitors and manages iSCSI sessions on an EqualLogic volume, ensuring that there are paths
available to each member hosting the volume so that I/O can send directly to that member.
In previous HIT Kit releases, EHCM established two connections to each PS Series array member hosting
the volume by default, up to a maximum of six connections. This approach ensured maximum
availability and performance, but was inefficient in the Microsoft Failover Clustering environment.
Because the non-CSV volume only accessed one cluster node any point in time, only the active node
that owned the volume made use of iSCSI sessions; the connections from other passive node(s)
remained idle but consumed resources on the PS Series group.
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EqualLogic HIT Kit 3.4.1/3.4.2 — New Features to Enhance Microsoft Failover Clustering Support
To reduce the overhead of idling connections from passive nodes while still maintaining desired
performance and availability, EHCM in HIT Kit 3.4.1/3.4.2 adds an intelligent algorithm to dynamically
allocate iSCSI connections as follows:
• If the volume is a CSV volume that can be simultaneously accessed from different cluster
nodes, EHCM establishes two connections per PS Series array member.
• If the volume is not a CSV volume:
o If the node owns the volume, then EHCM establishes two connections per PS Series
array member, up to six connections for that volume.
o If the node does not own the volume, then EHCM only establishes two connections,
regardless of the number of array members in the group. If the volume resides on
multiple PS Series array members, one or two array members may not have an iSCSI
connection.
• EHCM actively monitors the state of the volume. If the state changes, the number of
connections adjusts accordingly. For example, if a volume with three members moves from
node A to node B, then EHCM will reduce the number of connections on node A from six to two,
and increase the number of connections on node B from two to six.
Users will no longer see behavior in which each volume has the same number of connections from each
cluster node. The number of connections on the volume depends on how the volume is used in the
cluster node, and can vary among the nodes. This new feature works with all PS-Series arrays supported
in the Dell Failover Cluster and helps maintain the desirable performance/availability while reducing the
excess iSCSI connections.
Information on Dell Failover Cluster Solutions
For more information on Dell Failover Cluster Solutions, see:
Cluster documentation:
http://docs.us.dell.com/support/edocs/systems/clusters/
Cluster Configuration Support Matrices:
http://www.dell.com/content/topics/global.aspx/sitelets/solutions/cluster_grid/clustering_ha?c=us&cs=555
&l=en&s=biz&~page=3&~tab=4
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