TECHNICAL REPORT

USING TIERED STORAGE IN A PS SERIES SAN ABSTRACT

This Technical Report describes the concepts and benefits of tiered storage, and describes how to take advantage of storage pools and other features of EqualLogic PS Series Firmware to implement tiered storage in a PS Series SAN

TR1027

V2.1

Copyright © 2010 Dell Inc. All Rights Reserved.

Dell EqualLogic is a trademark of Dell Inc.

All trademarks and registered trademarks mentioned herein are the property of their respective owners.

Possession, use, or copying of the documentation or the software described in this publication is authorized only under the license agreement specified herein.

Dell, Inc. will not be held liable for technical or editorial errors or omissions contained herein. The information in this document is subject to change.

June 2010

WWW.DELL.COM/PSseries

PREFACE Thank you for your interest in Dell EqualLogic™ PS Series storage products. We hope you will find the PS Series products intuitive and simple to configure and manage.

PS Series arrays optimize resources by automating volume and network load balancing. Additionally, PS Series arrays offer all-inclusive array management software, host software, and free firmware updates. The following value-add features and products integrate with PS Series arrays and are available at no additional cost:

Note: The highlighted text denotes the focus of this document.

• PS Series Array Software

o Firmware – Installed on each array, this software allows you to manage your storage environment and provides capabilities such as volume snapshots, clones, and replicas to ensure data hosted on the arrays can be protected in the event of an error or disaster.

Group Manager GUI: Provides a graphical user interface for managing your array

Group Manager CLI: Provides a command line interface for managing your array.

o Manual Transfer Utility (MTU): Runs on Windows and Linux host systems and enables secure transfer of large amounts of data to a replication partner site when configuring disaster tolerance. You use portable media to eliminate network congestion, minimize downtime, and quick-start replication.

• Host Software for Windows

o Host Integration Tools

Remote Setup Wizard (RSW): Initializes new PS Series arrays, configures host connections to PS Series SANs, and configures and manages multipathing.

Multipath I/O Device Specific Module (MPIO DSM): Includes a connection awareness-module that understands PS Series network load balancing and facilitates host connections to PS Series volumes.

VSS and VDS Provider Services: Allows 3rd party backup software vendors to perform off-host backups.

Auto-Snapshot Manager/Microsoft Edition (ASM/ME): Provides point-in-time SAN protection of critical application data using PS Series snapshots, clones, and replicas of supported applications such as SQL Server, Exchange Server, Hyper-V, and NTFS file shares.

o SAN HeadQuarters (SANHQ): Provides centralized monitoring, historical performance trending, and event reporting for multiple PS Series groups.

• Host Software for VMware

o Storage Adapter for Site Recovery Manager (SRM): Allows SRM to understand and recognize PS Series replication for full SRM integration.

o Auto-Snapshot Manager/VMware Edition (ASM/VE): Integrates with VMware Virtual Center and PS Series snapshots to allow administrators to enable Smart Copy protection of Virtual Center folders, datastores, and virtual machines.

Current Customers Please Note: You may not be running the latest versions of the tools and software listed above. If you are under valid warranty or support agreements for your PS Series array, you are entitled to obtain the latest updates and new releases as they become available.

To learn more about any of these products, contact your local sales representative or visit the Dell EqualLogic™ site at http://www.equallogic.com. To set up a Dell EqualLogic support account to download the latest available PS Series firmware and software kits visit: https://www.equallogic.com/secure/login.aspx?ReturnUrl=%2fsupport%2fDefault.aspx

TABLE OF CONTENTS Preface ................................................................................................................................... ii Revision Information ............................................................................................................. 3 Introduction ............................................................................................................................ 4

What is tiered storage? .................................................................................................... 4 Why implement tiered storage? ...................................................................................... 4 How does a PS Series SAN support tiered storage? ....................................................... 4 Using Storage Pools to Optimize Price/Performance ..................................................... 7 Using Storage Pools to Segment Data by Organization ................................................. 7 Using Storage Pools to Segment Data by Application ................................................... 7 Tiered Storage within a Single Storage Pool .................................................................. 7

Subvolume Tiering by I/O Load with PS series XVS ........................................................... 8 Planning and Design Considerations ..................................................................................... 9

What business problem must be solved? ...................................................................... 10 Are there special organizational requirements? ............................................................ 10 What service agreements must be met? ........................................................................ 10 Is a tiered solution needed? ........................................................................................... 10 What are the storage capacity and performance requirements of each application? .... 10 Does an XVS make sense? ........................................................................................... 11 What are the capacity and performance characteristics of the available storage? ........ 11 Which RAID level(s) are appropriate for each storage pool? ....................................... 11 How will existing data be migrated into the new environment? .................................. 11

Examples of Tiered Storage Designs ................................................................................... 11 A Single Storage Pool ................................................................................................... 12 Two Storage Pools ........................................................................................................ 13 Three or More Storage Pools ........................................................................................ 13

Preparing for Deployment .................................................................................................... 14 Assign Applications to Tiers ......................................................................................... 14 Determine Resource Requirements for Each Tier ........................................................ 14 Plan Storage Pools ........................................................................................................ 15 Plan Volumes and Assign them to Storage Pools ......................................................... 15

Deploying ............................................................................................................................. 15 Set Up, and/or Add Members to a PS Series Group ..................................................... 15 Create Storage Pools within the Group ......................................................................... 15 Creating a Storage Pool ................................................................................................ 16 Assign Members to Storage Pools ................................................................................ 17 Assigning Members to Storage Pools ........................................................................... 17 Create Volumes and Assign Them to Storage Pools .................................................... 17 Creating and Assigning a Volume to a Storage Pool .................................................... 18

Summary .............................................................................................................................. 20

REVISION INFORMATION The following table describes the release history of this Technical Report.

Revision Date Document Revision

1.0 November 2006 Initial Release 2.0 April 2009 Formatted with new template 2.1 June 2010 Revised content and updated template

The following table shows the software and firmware used for the preparation of this Technical Report.

Vendor Model Software Revision

Dell EqualLogic™ PS Series Firmware V 3.0 and higher

The following table lists the documents referred to in this Technical Report. All PS Series Technical Reports are available on the EqualLogic website: http://www.equallogic.com/resourcecenter/documentcenter.aspx

Vendor Document Title

Dell EqualLogic™ Choosing a Member RAID Policy Technical Report

Dell EqualLogic™ Network Connection and Performance Guidelines Technical Report

Dell EqualLogic™ Group Administration Manual

Dell EqualLogic™ Installation and Setup Guide

INTRODUCTION Dell™ EqualLogic™ PS Series products support deployment in a tiered SAN architecture. This technical report will outline the basics of tiered storage and how a SAN built from multiple PS Series arrays can be used to implement a tiered storage architecture. In addition, planning and design considerations, preparing for deployment, and typical steps involved in an actual deployment are discussed.

What is tiered storage?

Tiered storage is storage that is differentiated and optimized for the type of data that it stores. Different types of data have different IO patterns, different performance requirements, different costs, different values to the company and different associated service level agreements. A tiered storage system provides different types of storage suited to the unique needs of the different types of data stored in the system. Instead of simply optimizing for maximum storage utilization, a tiered storage system allows optimization for a combination of conflicting requirements, including maximum application performance and lowest cost.

Why implement tiered storage?

Tiered storage is important because IT resources are finite. In the past, all data was usually stored on high-speed, high-cost disk. While this approach is simple, it is expensive to implement and maintain with today’s exploding data storage requirements. Some data supports mission-critical, real-time applications; other data needs to be retained (although seldom accessed) for years to meet regulatory requirements. Much of the data stored today has requirements between these two extremes, but it might have Service Level Agreements (SLAs) which impose other restrictions or requirements that are difficult to address in a one-size-fits-all storage environment. Implementing storage tiers that provide the appropriate levels of performance, availability, redundancy, fault-tolerance and SLA compliance for each type of data allows businesses to meet these conflicting requirements at the lowest cost.

How does a PS Series SAN support tiered storage?

A PS Series SAN (also known as a PS Series group) is a Storage Area Network (SAN) comprised of one or more PS Series arrays connected to an IP network. Individual PS Series arrays that are part of a group are called members. Each member is assigned to a storage pool (more about this important concept later). When a group contains more than one member, those members can provide different capacity and cost levels, and be configured to use different RAID levels. These characteristics, along with the ability to easily move volumes into specific storage pools without any interruption in service, can be used to implement tiered storage without disrupting applications.

Figure 1 shows a PS Series group with multiple members in a single storage pool.

Figure 1: Multiple members in a single storage pool.

When a PS Series group contains multiple members, the overall storage space can be divided into separate pools, providing an even greater level of control over storage resources in the SAN. Given enough member arrays (a pool must contain at least one member) a PS Series group can be divided into up to four pools. A pool acts like a SAN within a SAN, creating an isolated storage environment within the overall SAN. Figure 2 shows the same PS Series group divided into two pools.

Figure 2: Two tiers of data storage implemented as two pools.

PS Series GroupDefault Storage Pool

Member1RAID 10

Member2RAID 5

Member3RAID 5

Member4RAID 50

Switched Gigabit Ethernet Network

Web Server Volume

Regulatory Data Volume 1

Regulatory Data Volume 2

E-Mail Volume

PS Series GroupDefault Storage Pool

Member2RAID 5

Member3RAID 5

Member4RAID 50

Regulatory Data Volume 1

Regulatory Data Volume 2

E-Mail VolumeStorage Pool 1

Web Server Volume

Member1RAID 10

Switched Gigabit Ethernet Network

Volumes assigned to a storage pool remain within that storage pool unless they are moved by the administrator. Load balancing is done automatically within the storage pool, using storage resources provided by its members.

Whether or not multiple storage pools are deployed, the entire SAN (including all storage pools) is managed through a single administrative interface as shown in Figure 3. This simplifies administration of the group as a whole, and also makes it possible to move volumes and even members between storage pools as business requirements change. Examples which follow will make the benefits of implementing tiered storage in a PS Series group clearer.

Figure 3: Management of all storage pools from a single interface.

Mission-critical applications (particularly those that involve lots of small, random writes) are often best stored on PS Series arrays with 15,000 RPM SAS drives or SSD configured as RAID 10. This results in storage optimized for high-speed random-access with good capacity. Alternatively, lower capacity requirements could use PS Series arrays with SSDs to achieve even higher IOPS at an affordable cost.

For many applications, this performance is not required for volumes providing bulk storage of less frequently needed data. These volumes might best be stored on PS Series arrays with 7,200 RPM SATA drives configured as RAID 6, resulting in storage optimized for greater capacity and lower cost.

Note: For a more complete discussion of creating a SAN that meets an organization’s requirements please see Planning and Design Considerations later in this report. A discussion of various RAID policy options available in the EqualLogic PS Series and the advantages of each may be found in the PS Series Technical Report, PS Series Storage Arrays Choosing a Member RAID Policy. This document may be downloaded from the EqualLogic support site.

Using Storage Pools to Optimize Price/Performance

When there is mission-critical data to protect, as well as a need for bulk storage, one common approach is to create two storage pools to meet these two very different needs. The storage pool for the mission-critical data would contain the highest performance arrays, configured with the RAID level that best supports the application’s read and write pattern. Only mission-critical applications are provided resources from this storage pool. The other storage pool could contain high-capacity arrays configured to maximize storage capacity and minimize cost for long-term storage.

This model works well when adding additional arrays to an existing group. New arrays can be added to the appropriate pool, or existing arrays can be seamlessly migrated from one storage pool to another storage pool, with no downtime. For example, if the performance storage pool was configured with a SATA array in RAID10, a new PS Series array with SAS or SSD drives configured in RAID10 might be added to the storage pool for mission-critical data. The PS Series array with SATA drives in RAID10 could then be migrated from the mission-critical storage pool to the long-term storage pool to increase that storage pool’s capacity and then converted to RAID50 after the migration. Again, all this happens online, without any downtime for the SAN or applications.

Using Storage Pools to Segment Data by Organization

A very common scenario is this: Each business unit is responsible for their own storage costs, and each understandably wants to guarantee exclusive access to the storage they pay for.

This requirement is readily met by creating separate storage pools for each business unit. By placing each business unit’s data in its own storage pool and setting the access controls to ensure that only that business unit has access to that storage pool, each of the business units is assured exclusive use of their own storage. Within each storage pool you still get the benefits of PS Series automatic load-balancing, and you retain the ability to manage all the storage in the group from a single interface.

Using Storage Pools to Segment Data by Application

Storage pools can also be used to isolate critical applications, while retaining the management benefits of a single SAN. By creating a separate storage pool for the application data and setting the access controls so that only the servers associated with that application have access to that storage pool, data can be physically separated while still keeping a single PS series group to manage all the storage through a single management interface. Each storage pool still gets the benefits of PS Series automatic load-balancing and management.

Tiered Storage within a Single Storage Pool

It is also possible to implement tiered storage within a single storage pool. By creating a heterogeneous storage pool (one containing multiple members with different RAID levels), and letting the SAN automatically migrate volumes to the most appropriate RAID level or specifying a volume RAID preference, the IT staff may obtain many of the benefits of multiple storage pools with minimal effort. This type of arrangement is often appropriate for larger environments. Smaller environments are typically best served by using arrays with similar disk types and the same RAID level, using classic load balancing algorithms to distribute the data across more spindles for easy to manage, scalable performance.

SUBVOLUME TIERING BY I/O LOAD WITH PS SERIES XVS The XVS models use both low latency SSD and standard 15K SAS drives to provide two tiers of storage within a single EqualLogic member. These members of the EqualLogic family are designed to work with tiered workloads, for example, workloads where some of the data is accessed very frequently on a consistent basis, and some of the data is accessed much less frequently.

The EqualLogic advanced load balancing engine is able to operate on parts of volumes based on the I/O load. The software tracks the capacity in use by access frequency, and categorizes it into one of three classes; high I/O, medium I/O, and low I/O. Based on this categorization, the XVS is able to evaluate the data residing on the two tiers of storage (SSD and 15K HDD) within the array and determine if there is some part of the data on the HDD that would be better served by the SSD (i.e. high I/O data). If so, then the data currently residing on the SSD tier is evaluated to determine if there is low I/O data that can be relocated to the HDD tier to make space available for the high I/O data. If so, the XVS will adjust the placement of the data accordingly. If there is no low I/O data in SSD then the SSD tier is searched for medium I/O data, and a similar exchange takes place.

By intelligent use of spare I/O cycles, the impact of the data movement on user workloads is eliminated, and the workload gradually increases in IOPS and decreases in latency over the course of time, typically started in minutes and completed in just a few hours. If usage patterns change, the XVS will self-adjust to the new work pattern, and again accelerate the relevant portion of the data. An example of a workload that started out on HDD and was migrated to SDD by an XVS system while improving in performance is shown below in Figure 4.

Figure 4: A workload being accelerated over time

Because of the unique nature of the XVS load balancing capabilities, it is generally a good idea (although not required) to isolate XVS arrays into a separate storage pool.

As an additional benefit, the XVS systems set aside a small portion of their total SSD capacity to act as an enhanced write cache to help accelerate random write operations. This can benefit databases such as data warehouses that frequently need to dump several gigabytes of data into the database quickly. SANHQ 2.1 is able to show both the distribution of data capacity by I/O load, as well as the load on the XVS enhanced write cache as shown below in Figures 5 and 6.

Figure 5: I/O Load Distribution from SANHQ

Figure 6: XVS Enhanced Write Cache Utilization from SANHQ

PLANNING AND DESIGN CONSIDERATIONS It is important to have a well-considered plan in place before beginning to implement tiered storage. When designing a tiered storage solution, there are a number of factors to consider. These include, but are not limited to, the following:

• What business problem must be solved?

• Are there special organizational requirements?

• What service agreements must be met?

• Is a tiered solution needed?

• What are the storage capacity and performance requirements of each application?

• Does an XVS make sense?

• What are the capacity and performance characteristics of the available storage?

• Which RAID level(s) are appropriate for each storage pool?

• How will existing data (if any) be migrated into the new environment?

The following sections provide more in-depth information about each of these considerations.

What business problem must be solved?

The requirements of the business problem should drive the planning and design work. What business problem needs to be solved with this SAN deployment or upgrade? Is there a need to store data from additional applications in the SAN in the future? Do business units require exclusive use of their own storage resources? Are there new capabilities of PS Series SAN that provide new options to solve the business problems?

Are there special organizational requirements?

Organizational requirements, such as a need to guarantee a business unit exclusive access to storage, can complicate the effort to solve the primary business problem. Be sure to factor in any special organizational requirements during the planning and design phase of the project.

What service agreements must be met?

In addition to any special organizational requirements, service agreements need to be accounted for when designing the solution. Formal commitments for levels of performance, availability, redundancy, and fault tolerance, for example, will affect many aspects of the design. Addressing these issues early ensures that the design will meet the service commitments in addition to solving the primary business problem.

Is a tiered solution needed?

The high-level considerations discussed above will help determine whether a single-pool storage design is suitable, or if multiple tiers of storage should be set up using separate storage pools. While multiple tiers of data are still managed from a single interface regardless of the number of storage pools in the group, a single-pool group is easier to implement and maintain than a multi-pool group. PS Series best practices recommend using as few storage pools as possible and allowing the PS Series firmware to handle load balancing and assignment of volumes to get the best utilization from the available storage.

What are the storage capacity and performance requirements of each application?

Since storage pools use only their own resources, each storage pool must have the storage capacity, IOPS and throughput to serve the applications that are assigned to it, regardless of the overall capacity of the group. Be sure to design each storage pool to have enough capacity for all the data

that will be stored on it, plus enough capacity for any snapshots or data replication that will be required.

Does an XVS make sense?

The XVS systems can add tremendous value to a customer workload. The workload must, however, be naturally tiered, and be well-suited to SSD acceleration and need SSD levels of performance. For example, a VDI system using a tool such as VMware View/Composer or Citrix XenDesktop that concentrates a large portion of the reads into a relatively small portion of the total capacity is an excellent fit for the XVS. Another example is a database, such as a college registration system, where the indexes and course catalogue will be frequently accessed, but individual student records, which make up the bulk of the database capacity, are infrequently accessed. Approximately 20% of the XVS capacity is SSD based, so workloads that are uniformly busy over a large portion of the data, or which are not consistent in which part of workload is frequently accessed, may be better served by other EqualLogic array models.

What are the capacity and performance characteristics of the available storage?

The specific types of arrays you have can affect how you construct storage pools. If you have arrays with varying drive speeds and storage capacity, you can optimize the performance of your overall SAN through careful consideration of these factors. Consider using arrays with the fastest drives for real-time or transactional data, while using those with the greatest storage capacity for bulk storage of less time-critical data.

Which RAID level(s) are appropriate for each storage pool?

The ability to assign different RAID levels (5, 6, 10, or 50) to each member of a storage pool increases your operational flexibility. The only constraint on RAID level assignments is that, to guarantee best performance, you should not assign the same RAID level to members of a storage pool that have different drive speeds.

For more information on RAID level options, see the PS Series Technical Report, PS Series Storage Arrays Choosing a Member RAID Policy, available at the EqualLogic website.

How will existing data be migrated into the new environment?

When moving storage for an application onto the SAN, what tools are available to migrate the data? PS Series best practices call for migrating application data onto the SAN using a file-level program such as Robocopy for Windows® systems or cp for UNIX® or Linux, rather than using disk imaging tools. Applications such as Exchange® have their own utilities that are designed to migrate their data safely. When migrating the data it is important to remember to use the appropriate settings of the copy tool to preserve ownership and permissions.

EXAMPLES OF TIERED STORAGE DESIGNS To demonstrate some of the possibilities, the following examples of common tiered storage designs are included. When viewing these examples, keep in mind that (except when being migrated from one member to another) volumes are stored in only one storage pool, and each member array must belong to one, and only one, storage pool.

Note: The number of members and volumes used in the following examples were chosen to simplify the explanation of each example, and are not meant to constrain the design in any

way. Any number and combination of arrays, consistent with the release notes of the firmware version used, is supported.

A Single Storage Pool

In many cases, a single storage pool will best meet the storage needs of an organization. Figure 7 shows a single-pool SAN with four member arrays and two volumes, one for production application data (a database, email stores, and file & print data) and one for backup and archive data.

Figure 7: All data in a single storage pool

A design like this offers a lot of flexibility without the use of multiple storage pools. In the most basic design, all members may be the same disk type and configured with the same RAID level. The PS Series firmware automatically distributes data intelligently across the members. This homogeneous storage pool design allows the data to be redistributed efficiently as the application usage of the storage varies over time and is often the most efficient for many organizations.

Thanks to the flexibility of the PS Series firmware, it is also possible to implement a heterogeneous storage pool design, where the members are configured with different RAID levels and/or consist of different models of PS Series arrays. Each RAID level offers its own combination of performance and availability. The PS Series firmware can take advantage of this by automatically moving data volumes with high IO to members set to RAID-10 to optimize performance for that data’s usage pattern.

In addition to permitting the firmware to determine the most appropriate placement of data, it is possible to specify a preferred RAID level for a volume. Specifying a preference overrides automatic load balancing for that volume. If capacity is available with the requested RAID level, the PS Series firmware will honor the request and place the volume in that RAID level. If capacity is not available, the volume will be distributed within the storage pool normally.

The RAID preference settings are on the Advanced tab of the Modify volume settings dialog box.

Two Storage Pools

A common choice to provide separation of application data from backup and archive data, or more control over which volumes run on which hardware is to implement two storage pools, as shown in Figure 8. This figure shows four member arrays and two volumes deployed in two storage pools, one for production application data and one for backup and archive data. The difference here is that each volume is in a different storage pool with storage resources dedicated to that function.

Figure 6: Separating application data from backup and archive data with two storage

pools.

Aside from management, each storage pool is independent and provides all the options available for a single storage pool. Thus, each storage pool can be homogenous (all members of the storage pool configured at the same RAID level, for example) or heterogeneous (with some arrays at RAID-10 levels and arrays at other RAID levels within the same storage pool).

Be sure to consider the amount of storage available within each storage pool. Not only must the storage capacity of the PS Series group as a whole be large enough to contain all of the volumes, but the capacity of each storage pool must be large enough to contain the volumes that are stored within the storage pool.

Three or More Storage Pools

One common scenario is the need to optimize the performance of a business critical database application. The concepts presented in the two storage pool example can be further extended to three or more storage pools, as shown in Figure 9. In this example, three storage pools are used: one for the database, one for the other applications, and one for backup and archive data.

Figure 9: A third storage pool allows for further application data tiering.

In this design, the member (or members) with the best random access performance are placed in the Database Storage Pool to optimize the performance of the database. As noted previously, each storage pool may be homogenous or heterogeneous to optimize the performance of the overall environment.

As with the two-pool design, the storage capacity of each storage pool must be considered, in addition to that of the group as a whole.

PREPARING FOR DEPLOYMENT Performing these activities prior to beginning the actual deployment permits the IT team to be develop the plan on paper so that the actual implementation will proceed smoothly. Depending on the size and complexity of the storage plan, it may take multiple iterations to come up with optimal tier, storage pool, and volume assignments. Deployment preparation tasks include:

• Assigning applications to tiers

• Determining resource requirements for each tier

• Planning storage pools

• Planning volumes and assigning them to storage pools

Assign Applications to Tiers

After taking into account the design considerations discussed above, organize applications into one to four tiers of storage.

Determine Resource Requirements for Each Tier

Given the storage and throughput requirements of the applications in each tier, determine the total resource requirements of each tier. Remember to plan adequate space for snapshots, replication, and expected near-term growth. Consult the product documentation for guidance on sizing these resources properly.

Plan Storage Pools

Determine if the available stock of PS Series arrays can be divided into storage pools in such a way as to meet the resource requirements for each of the planned tiers. Be sure to consider the impact of RAID-level selection on capacity within each storage pool.

Remember that resources cannot be shared across storage pools; each array belongs to only one storage pool in a PS Series group. Additional arrays may be needed to create storage pools that meet the design requirements. The PS Series product line includes arrays with a variety of speed, capacity, and price points, enabling businesses to more easily meet their storage needs.

Plan Volumes and Assign them to Storage Pools

Determine what volumes are required. Determine the appropriate size (including reserve space for snapshots) of each volume, and then assign them to the appropriate storage pools.

When this process is complete for all volumes that will be included in a given storage pool, confirm that the members assigned to that storage pool are capable of providing the necessary space.

DEPLOYING This section describes a sequence of steps that the IT staff will typically complete when deploying a tiered storage environment. These steps are:

• Set up, and/or add members to a PS Series group

• Create storage pools within the group

• Assign members to storage pools

• Create volumes and assign them to storage pools

Set Up, and/or Add Members to a PS Series Group

If the SAN is being built from scratch, install the hardware and connect the serial cable (only needed for the initial setup) and network cables on the array that will be the first group member. See the PS Series Installation and Setup guide for detailed installation and setup information.

If there is an existing PS Series group to which members are being added, follow the instructions under, “Adding Members to an Existing Group” in the PS Series Group Administration manual.

For optimal performance, connect and configure multiple network interfaces on each array that is a group member. See the Technical Report Network Connection and Performance Guidelines on the EqualLogic Customer Service website for more information.

See “Customizing the Group” in the PS Series Group Administration manual for instructions on applying CHAP and other Access Controls to the members of the group.

After creating the group, start the Group Manager by connecting to the group IP address with a Java enabled browser and entering the group administration name and password when requested.

Create Storage Pools within the Group

After the members have been added to the group, the storage pools that will contain the members can be created following the planned the number of storage pools and their names. The following steps demonstrate the process of creating one storage pool within the group.

Note: Additional information about creating and working with storage pools is available in Chapter 4 of the Group Administration guide.

Creating a Storage Pool

Follow these steps to create a storage pool within the group:

1. Open the GUI to the Group Summary window.

2. In the Activities panel, click Create storage pool. This opens the Create Storage Pool dialog box.

Figure 10: Create a storage pool

3. Enter a storage pool name and Description.

4. Click OK to create the storage pool. The new empty storage pool appears in the Storage Pools and Group Members panel of the Group Summary window.

Figure 11: The new empty storage pool appears in this pane.

Assign Members to Storage Pools

After creating all the storage pools, members must be assigned to the storage pools. The planning phase will have determined which members will be assigned to which storage pools. Follow these steps to assigning a member to a storage pool.

Assigning Members to Storage Pools

1. From the Members window in the GUI, right-click the name of a member.

2. In the shortcut menu that appears, click Modify Member Settings. This opens the Modify Member Settings dialog box.

Figure 12: Move a member into a new storage pool

3. Modify the Member name and description if necessary.

4. Select the storage pool to which this member is assigned in the plan.

5. Click OK. The member becomes part of the assigned storage pool.

Create Volumes and Assign Them to Storage Pools

After the storage pools are created and the members are assigned to them, the next step is to create the required volumes, assign them to the correct storage pools, and set the access control for each volume. The following steps demonstrate the process for one volume.

Note: Additional information about creating and working with volumes is available in Chapter 5 of the Group Administration guide.

Creating and Assigning a Volume to a Storage Pool

Follow these steps to create a volume and simultaneously assign it to a storage pool:

1. Open the GUI to the Group Summary dialog box.

2. In the Activities panel, click Create volume. This opens the Create Volume dialog box to Step 1 of 4 – Volume Settings, as shown in Figure 13.

Figure 13: Create a volume and assign it to a storage pool with this wizard.

3. Enter the Volume name and optionally a Description.

4. In the Storage Pool list, select the storage pool to which the volume will be assigned.

5. Click Next to open Step 2 of 4 – Space reserve in the Create Volume dialog box shown in Figure 14.

Figure 14: Space Reserve Controls for the volume.

6. Enter the Volume size.

7. Optionally, make the volume Thin Provisioned.

8. Adjust the Snapshot reserve percentage if desired.

9. Click Next to open Step 3 of 4 – iSCSI Access in the Create Volume dialog box shown in Figure 15.

Figure 15: Set Access Controls for the volume.

10. Configure the Access Control method required for this volume.

11. Optionally, enable shared access to the iSCSI target from multiple initiators if this volume will be shared in a cluster.

12. Click Next to open Step 4 of 4 – Summary in the Create Volume dialog box.

13. Click Finish to finish creating the volume.

SUMMARY A tiered storage solution provides different types of storage for each tier of applications and data, enabling businesses to optimize performance of the SAN while minimizing the overall cost of the implementation. An iSCSI SAN built around PS Series arrays enables easily implemented tiered storage systems with multiple pools of storage, while still retaining all the benefits typically associated with the PS Series including automatic load balancing, single-screen management of the entire SAN, storage virtualization, and performance that increases as the SAN grows.

Technical Support and Customer Service

Dell’s support service is available to answer your questions about PS Series SAN arrays. If you have an Express Service Code, have it ready when you call. The code helps Dell’s automated-support telephone system direct your call more efficiently.

Contacting Dell

Dell provides several online and telephone-based support and service options. Availability varies by country and product, and some services might not be available in your area.

For customers in the United States, call 800-945-3355.

Note: If you do not have access to an Internet connection, contact information is printed on your invoice, packing slip, bill, or Dell product catalog.

Use the following procedure to contact Dell for sales, technical support, or customer service issues:

1. Visit support.dell.com or the Dell support URL specified in information provided with the Dell product.

2. Select your locale. Use the locale menu or click on the link that specifies your country or region.

3. Select the required service. Click the “Contact Us” link, or select the Dell support service from the list of services provided.

4. Choose your preferred method of contacting Dell support, such as e-mail or telephone.

Online Services

You can learn about Dell products and services using the following procedure:

1. Visit www.dell.com (or the URL specified in any Dell product information).

2. Use the locale menu or click on the link that specifies your country or region.