Features and Benefits of HSG80 ACS 8.6P Data Replication Manager

ManualsBrandsHP ManualsSoftwareHP StorageWorks EMA/ESA/MA Replication Software

White Paper

October 2001

15F2-0801A-WWEN

Prepared by:

Enterprise Storage Group

Compaq Computer Corporation

Contents

Introduction .................................3

SANworks Data Replication

Manager .......................................5

DRM Features and Benefits ......6

Data Replication Process ..........9

Replication Modes .....................9

Remote Copy Set ....................11

Association Set........................11

Basic DRM Configuration .........12

Long Distance Solutions ..........12

Extended DRM over ATM

Configuration ...........................12

Extended DRM over IP

Configuration ...........................13

Special Purpose DRM

Solutions....................................14

Bi-directional DRM

Configuration ...........................14

Stretch Cluster Support ...........15

DRM Dual Switch/Single Site

Configuration ...........................16

Single Switch ...........................17

Single Fabric............................18

Supported Hardware and

Software .....................................18

Supported Servers and

Operating Systems ..................18

Fibre Channel Switches...........19

Storage Arrays.........................19

Hard Drive ...............................20

Required Software ...................20

Glossary.....................................20

Features and Benefits of HSG80

ACS 8.6P Data Replication

Manager

Abstract: The Compaq SANworks Data Replication Manager

(DRM) is controller-based data replication software for disaster

tolerance and data movement solutions. DRM allows all data to be

mirrored between two different storage arrays, which can be in

separate geographic locations. Properly configured, DRM can be a

complete disaster-tolerant storage solution that guarantees data

integrity in case of a storage subsystem or site failure.

Summary of content (22 pages)

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White Paper October 2001 15F2-0801A-WWEN Prepared by: Enterprise Storage Group Compaq Computer Corporation Contents Introduction .................................3 SANworks Data Replication Manager .......................................5 DRM Features and Benefits ......6 Data Replication Process ..........9 Replication Modes .....................9 Remote Copy Set ....................11 Association Set ........................11 Basic DRM Configuration .........12 Long Distance Solutions ..........
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 2 Notice 15F2-0801A-WWEN © 2001 Compaq Computer Corporation. Compaq, the Compaq logo, AlphaServer, ProLiant, StorageWorks, SANworks, Tru64, and OpenVMS are trademarks of Compaq Information Technologies Group, L.P. Microsoft, Windows, and Windows NT are trademarks of Microsoft Corporation. UNIX is a trademark of The Open Group. All other product names mentioned herein may be trademarks of their respective companies.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager Introduction Data Replication Manager (DRM) provides remote disk mirroring by connecting primary RAID systems to remote storage RAID systems. In the event of a disaster at the primary site, a copy of the data is safe on the remote storage system and available for immediate connection to an alternate host.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager • Up to 12 remote copy sets per association set • New and improved procedures for AIX, OpenVMS, NetWare, Solaris, Tru64, Windows 2000, and Windows NT • 4 • Ten documented failover and failback procedures covering planned and unplanned contingencies. • Documented procedures for moving data, performing multisite replication, and growing a storage set.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 5 SANworks Data Replication Manager The Compaq SANworks HSG80 ACS 8.6P Data Replication Manager is data replication software for disaster tolerance and data movement solutions. The software works with the StorageWorks Fibre Channel MA8000/EMA12000/EMA16000 and RA8000/ESA12000 storage systems. DRM allows all data to be mirrored between storage elements in two different storage arrays that can be in separate geographic locations.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 6 DRM Features and Benefits This section describes the features of DRM and the benefits they provide to the DRM solution. Disaster tolerance—The redundancy of the DRM hardware provides disaster tolerance. Each Modular Array (MA) has dual RAID controllers, mirrored cache, dual cache batteries, and dual power supplies.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 7 Zoning—Zoning allows a switched fabric to be partitioned into multiple zones. It limits a controller to a specified zone or zones and limits the number of controllers a server can see. This feature increases the number of servers allowed per SAN and enables the administrator to dedicate a zone for a specific function such as backup.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 8 Windows 2000 and Windows NT Large LUN Support—After enabling the Windows Large LUN feature within the operating system, DRM supports up to 64 LUNs in SCSI-2 mode or 63 LUNs in SCSI-3 mode. Note: A single DRM instance is limited to 12 remote copy sets and 12 non disaster-tolerant LUNs per site for a total of 36 LUNs. Even this exceeds the drive letter limit of Windows 2000 or Windows NT.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 9 • Shared ATM lines—The FC-to-ATM OSG can also support shared or multi-use ATM lines. A shared ATM line allows only one telecommunication link between sites, but the line bandwidth is divided between the two Fibre Channel fabrics. Another common application could be DRM and non-DRM use of the same shared ATM line. A shared ATM line may be used when the customer’s bandwidth requirements do not justify two separate dedicated ATM lines.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 10 System A I/O Complete Data System A Mirror of Data System A Figure 2: Synchronous transfer mode Asynchronous Transfer Mode With asynchronous mode, local and remote copy sets are not always identical. There is a delay between the time the local storage is updated and the time that the remote storage is updated.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 11 Remote Copy Set A remote copy set is a bound set of two units used for long distance mirroring. Each unit can be a single JBOD disk, RAID-0 stripeset, RAID 1 mirrorset, or RAID 0+1 Stripe-Mirrorset or RAID 3/5 RAID set. In Figure 4, the LUN Remote Copy Set (RCS1) consists of Unit A and Unit C. RCS2 consists of Unit B and Unit D. During replication, the local side of the remote copy set can be made visible to any of the hosts on the SAN.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 12 An association set can have up to 12 remote copy set members. All members of an association set must be on the same fabric to maintain controller cache coherency. When members are added to an association set, they are moved to the same initiator controller and fail over together. A maximum of 12 association sets, one per RCS, are available per pair of storage arrays running in DRM mode.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 13 Due to limitations in the OSG, a DRM over ATM solution is limited to what can be connected to the available 14 ports on each of the four 16-port switches. The following options are based on one port per HBA pair and two ports per HSG80 pair per switch.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 14 The FC-to-IP gateways do not have the same design limitations as FC-to-ATM gateways. The DRM-to-IP solution is limited to the same 20 switch fabrics as DRM over direct fiber solutions, which means that DRM over IP is currently limited to supporting up to 96 servers and 8 storage arrays. Initial versions of the FC-to-IP gateway support direct connection to at least one of the current Ethernet protocols (10 Mbps, 100 Mbps, or 1 Gbps).
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 15 As shown in Figure 8, there are two servers at each site. These site-specific pairs of servers could be clustered during normal operations to provide highly available applications. When the failure of one of the sites occurs, the application that was running at the failed site is moved to the backup member of the surviving cluster and started using the surviving storage and the other half of the surviving cluster.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 16 DRM Dual Switch/Single Site Configuration Compaq supports the DRM Dual Switch/Single Site configuration for those environments that only need local data protection in the event of local disasters or that are used as local test beds for operational DRM solutions. This solution uses only two switches, where each switch creates a fabric “in a box” instead of the multiswitch fabrics supported in the non-Dual Switch/Single Site DRM solutions.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 0 2 4 6 8 10 12 14 1 3 5 7 9 11 13 15 1 2 1 2 1 2 1 2 17 0 2 4 6 8 10 12 14 1 3 5 7 9 11 13 15 Figure 9: DRM Dual Switch/Single Site configuration Single Switch The Single Switch DRM solution is designed for small, single-site entry level tests and proof of concept demonstrations. This nondisaster-tolerant solution can also be used for producing copies of data needed for data migration or data mining.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 18 Single Fabric The Single Fabric DRM solution is designed for small, entry level tests and proof of concept demonstrations where some distance is needed between each of the two switches in the solution. This nondisaster-tolerant solution can also be used for producing copies of data needed for data migration or data mining. Fabric zoning is used to create two logical fabrics out of the one physical fabric.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 19 Table 2. Supported Servers Vendor Operating Systems Compaq–AlphaServer?TM OpenVMS and Tru64 Compaq–ProLiant Windows 2000, Windows NT, and NetWare IBM–RS6000 AIX Sun–Ultra SPARC and UE Solaris Table 3. Supported Operating Systems Vendor Operating System Versions Compaq Open VMS 7.2-1H1, 7.2, 7.3 Compaq Tru64 UNIX 5.1, 5.1A IBM AIX 4.3.3 Microsoft Windows NT 4.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 20 • ESA12000—Supports up to 72 disk drives per pair of controllers. • RA8000—Supports up to 24 disk drives per pair of controllers in an office cabinet. Hard Drive DRM supports the following disk drives when installed in the appropriate storage cabinet. Table 4.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 21 Constant Bit Rate (CBR)—Category of ATM service that supports a constant or guaranteed data rate. CBR supports applications that need a highly predictable transmission rate. Dual Switch/Single Site—A complete storage offering based on the DRM Dual Switch/Single Site for the Windows NT solution that provides the highest level of data availability in single-site environments.
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Features and Benefits of HSG80 ACS 8.6P Data Replication Manager 22 Quality of Service (QoS)—Each virtual connection in an ATM network has a service category. The performance of the connection is measured by the established QoS parameter, which is outlined by the ATM forum. Small Computer System Interface (SCSI)—An American National Standards Institute (ANSI) interface standard defining the physical and electrical parameters of a parallel I/O bus used to connect initiators to devices.