EMC Solutions for Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

Transcription

1 EMC Solutions for Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms EMC NAS Product Validation Corporate Headquarters Hopkinton, MA

2 Copyright 2007, 2008, 2009 EMC Corporation. All rights reserved. Published May, 2009 EMC believes the information in this publication is accurate as of its publication date. The information is subject to change without notice. THE INFORMATION IN THIS PUBLICATION IS PROVIDED AS IS. EMC CORPORATION MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Use, copying, and distribution of any EMC software described in this publication requires an applicable software license. For the most up-to-date listing of EMC product names, see EMC Corporation Trademarks on EMC.com. All other trademarks used herein are the property of their respective owners. Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms P/N H Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

3 Contents About this Document... 5 Chapter 1 Exchange Best Practices... 7 Recommendation #1 Separate the database files and log files... 8 Recommendation #2 Run Exchange Best Practices Analyzer... 8 Recommendation #3 Set up multiple DC/GC servers for fault tolerance... 8 Recommendation #4 Use Gigabit Ethernet... 8 Recommendation #5 Plan Exchange database capacity... 8 Recommendation #6 Plan Exchange log capacity... 9 Recommendation #7 Configure one mailbox database per storage group... 9 Chapter 2 Windows Servers Best Practices Recommendation #8 Disable client and services not required for iscsi on iscsi NICs Recommendation #9 Use the latest NIC driver Recommendation #10 Install the latest Microsoft iscsi initiator Recommendation #11 Modify the TCP/IP KeepAliveTime Recommendation #12 Increase the Microsoft Initiator time-out value Recommendation #13 Specify automatic restoration of iscsi connections Chapter 3 Networking Best Practices Recommendation #14 Use GbE switches with VLAN capabilities Recommendation #15 Dedicate switches or VLANs Recommendation #16 Use GbE NICs on the Exchange Server Recommendation #17 Use CAT6 cables for Gigabit Ethernet connectivity Recommendation #18 Set the network speed and duplexing properly Recommendation #19 Specify the adapter binding order Recommendation #20 Disable DNS on the iscsi storage network Chapter 4 Backup, Restore, and Replication Best Practices Recommendation #21 Use a deduplication appliance Recommendation #22 Use the Data Protection Manager Recommendation #23 Use RM for Celerra and VSS Recommendation #24 Schedule RM VSS snapshots appropriately Recommendation #25 Use two iscsi LUNs per Exchange storage group Recommendation #26 Create multiple Exchange storage groups Recommendation #27 Use the EMC NetWorker Module for Exchange Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 3

4 Contents Recommendation #28 Use Exchange Continuous Replication features appropriately...20 Recommendation #29 Use Automatic Volume Management...20 Recommendation #30 Separate active storage from passive storage...20 Recommendation #31 Plan for Microsoft Exchange continuous replication I/O levels...20 Recommendation #32 Use scripts for crash consistent replication in CLI mode...21 Chapter 5 Storage Best Practices...23 Recommendation #33 Use DISKPAR/DISKPART to align the NTFS volume...24 Recommendation #34 Set the LUN NTFS allocation unit...25 Recommendation #35 Plan storage layout for performance, not capacity...25 Recommendation #36 Use the building block approach to allocate spindles...25 Recommendation #37 Do not exceed 80% utilization of LUNs...25 Recommendation #38 Use Multiple Connections per Session (MC/S)...26 Recommendation #39 Use dedicated Celerra file systems...26 Recommendation #40 Use high rpm disk drives...26 Recommendation #41 Use RAID 1 for log files...26 Recommendation #42 Use RAID 1 with striping for database files...26 Recommendation #43 Use the latest Celerra software...26 Recommendation #44 Fail over Data Movers before rebooting...26 Chapter 6 Archiving Best Practices...27 Chapter 7 Recommendation #45 Use EMC SourceOne / Xtender...28 Recommendation #46 Use the File Level Retention (FLR) toolkit...28 Recommendation #47 Use the Celerra WORM file system...28 Recommendation #48 Use High IO throughput drives for Journaling folders...28 Virtual Infrastructure Best Practices...29 Recommendation #49 Use VMware vcenter Server...30 Recommendation #50 Make the VMware vcenter Server highly available...30 Recommendation #51 Use uncached mode...30 Recommendation #52 Be aware of virtual machine time considerations...30 Conclusion Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

5 About this Document Executive summary is one of the mission-critical applications for most businesses today. It is important to plan a Microsoft Exchange solution that can grow while maintaining optimum performance, high availability, and disaster recovery. This document is meant to be a resource for optimizing the performance of an Exchange 2007 storage configuration on an EMC Celerra by using iscsi. Introduction This document provides best practice recommendations for implementing EMC solutions for messaging. The messaging solution focuses on Microsoft Exchange 2007 on an EMC Celerra. Audience This document is intended to benefit IT administrators and system engineers who are responsible for planning and designing Exchange messaging systems using Celerra systems. It is assumed that the reader has a general knowledge of Microsoft Exchange 2007, Active Directory, and Celerra features and terminology. Terminology Active Directory: An advanced directory service introduced with Windows 2000 Server. It stores information about objects on a network and makes this information available to users and network administrators through a protocol such as LDAP. Automatic Volume Management (AVM): A feature of the Celerra Network Server that creates and manages volumes automatically, without manual volume management by an administrator. AVM organizes volumes into pools of storage that can be allocated to file systems. Data Mover: A Celerra Network Server cabinet component running the data access in real time (DART) operating system that retrieves files from a storage device and makes the files available to a network client. Disk volume: On Celerra systems, a physical storage unit as exported from the storage array. All other volume types are created from disk volumes. iscsi (Internet SCSI): A protocol for sending SCSI packets over TCP/IP networks. Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 5

6 About this Document iscsi initiator: An iscsi endpoint identified by a unique iscsi-recognized name that begins an iscsi session by issuing a command to the other endpoint (the iscsi target). iscsi target: An iscsi endpoint identified by a unique, iscsi-recognized name that executes commands issued by the iscsi initiator. RAID: Redundant array of independent disks. A method for storing information in which the data is stored on multiple disk drives both to increase performance and storage capacities and to provide redundancy and fault tolerance. RAID 1: A RAID method that provides data integrity by mirroring (copying) data onto another disk. This RAID type provides the greatest assurance of data integrity at the greatest cost in disk space. RAID 5: A RAID method in which data is striped across disks in large stripes. Parity information is stored so data can be reconstructed if needed. One disk can fail without data loss. Performance is good for reads but slower for writes. RAID group: The CLARiiON storage-system term for a Celerra disk group. In a CLARiiON storage system, a RAID group is a set of physical disks with a RAID type on which one or more LUNs are bound. Each RAID group supports only the RAID type of the first LUN bound on it; any other LUNs bound on it have that same RAID type. LUNs are distributed equally across all the disks in the RAID group. SP: Storage processor on a CLARiiON storage system. On a CLARiiON storage system, a circuit board with memory modules and control logic that manages the storage-system I/O between the host s Fibre Channel adapter and the disk modules. SP A: Storage processor A is a generic term for the first storage processor in a CLARiiON storage system. SP B: Storage processor B is a generic term for the second storage processor in a CLARiiON storage system. Volume Shadow Copy Service (VSS): A Windows service and architecture that coordinates various components to create consistent point-in-time copies of data called shadow copies. Related documents The following documents, located on Powerlink, provide additional, relevant information. Access to these documents is based on your login credentials. If you do not have access to the content listed below, contact your EMC representative: EMC Solutions for Microsoft Exchange 2007 EMC Celerra NS20 over iscsi Reference Architecture EMC Business Continuity for Microsoft Exchange 2007 Enabled by EMC Celerra, Replication Manager, VMware HA, DRS, and SRM Reference Architecture EMC Solutions for Microsoft Exchange 2007 Virtualization for EMC Celerra NS20 Reference Architecture Microsoft iscsi Software Initiator User's Guide Sizing Considerations for iscsi Replication on EMC Celerra Technical Note 6 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

7 Chapter 1 Exchange Best Practices This chapter presents these topics: Recommendation #1 Separate the database files and log files... 8 Recommendation #2 Run Exchange Best Practices Analyzer... 8 Recommendation #3 Set up multiple DC/GC servers for fault tolerance... 8 Recommendation #4 Use Gigabit Ethernet... 8 Recommendation #5 Plan Exchange database capacity... 8 Recommendation #6 Plan Exchange log capacity... 9 Recommendation #7 Configure one mailbox database per storage group... 9 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 7

8 Exchange Best Practices Recommendation #1 Separate the database files and log files In an Exchange environment, each storage group has its own set of transaction log files and database files. Transaction log files record changes made to all of the databases in a storage group. Transaction log files are not deleted until a full backup is performed on all databases in the storage group. In case of a database failure, the database can be repaired by restoring the most recent backup and then using the current log files to bring it up to date to the time at which the database failed. In case of transaction log failure, the transaction logs can be repaired from the database with minimal or no data loss. Therefore, it is highly recommended to ensure that database files and log files from the SAME Exchange storage group not share the same physical spindles. This prevents the possibility of losing an entire storage group in case of multiple disk failures. Recommendation #2 Run Exchange Best Practices Analyzer Customers often have issues with their Exchange environments due to misconfigured components. This can be remedied by using the Exchange Best Practices Analyzer. EXBPA scans the entire network and finds configuration, performance, and security issues that arise with Exchange. It collects information and settings from each Exchange Server and then applies rules, which are located in a configuration file, against the settings to find issues. The configuration file is updated frequently with new rules that are provided by Microsoft Exchange support engineers. EMC recommends that the EXBPA be run against all Exchange Servers after the installation is completed and to follow all of its recommendations. Additionally, EXBPA can be scheduled to run at intervals or through Microsoft Operations Manager (MOM). This ensures that the servers are running the latest best practices. Recommendation #3 Set up multiple DC/GC servers for fault tolerance Exchange relies heavily on Active Directory for DSAccess using the Domain Controller/Global Catalog (DC/GC). EMC recommends having a minimum of two Active Directory DC/GC servers per site for fault tolerance. As a general rule, the ratio of Exchange CPUs to DC/GC CPUs should be 4:1 for 32-bit and 8:1 for 64-bit, where for every four/eight Exchange Server physical processors there should be one DC/GC processor. At a minimum, there should be two DC/GC servers per site for fault tolerance. Recommendation #4 Use Gigabit Ethernet Maintaining optimal network performance is critical to the deployment of Exchange on iscsi because there is considerable network traffic generated by the Exchange Server For optimum network performance, use Gigabit Ethernet cabling, switches, and network interface cards for network connections between the Exchange Servers and the Celerra. Recommendation #5 Plan Exchange database capacity It is important to have enough storage capacity for the Exchange database. Exchange database capacity is more than the storage required to satisfy the mailbox quota on the Exchange database. There are several other factors such as database whitespace, database dumpster, and contend indexing to be considered when sizing for Exchange database capacity. Microsoft integrates the mailbox database sizing considerations into its storage calculator. EMC recommends using the Microsoft Exchange Storage Calculator for sizing Exchange database capacity. 8 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

9 Exchange Best Practices Recommendation #6 Plan Exchange log capacity Log capacity must be sized according to customer needs and is vital for a successful Exchange deployment. The Exchange log capacity needs to be planned according to a customer s user profile, backup frequency, and mailbox migration strategy. Microsoft integrates the Exchange log sizing considerations into its storage calculator. Use the Microsoft Exchange Storage Calculator for sizing Exchange log capacity. Recommendation #7 Configure one mailbox database per storage group Configuring one mailbox database on a storage group allows having a one-to-one relationship between the transaction log and its mailbox database. This improves backup and recovery management and minimizes downtime for the users of the mailbox database in the case of database corruption. Exchange 2007 Enterprise Edition eliminates the concern for growth, as it allows 50 storage groups on an Exchange Server. Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 9

10 Exchange Best Practices 10 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

11 Chapter 2 Windows Servers Best Practices This chapter presents these topics: Recommendation #8 Disable client and services not required for iscsi on iscsi NICs Recommendation #9 Use the latest NIC driver Recommendation #10 Install the latest Microsoft iscsi initiator Recommendation #11 Modify the TCP/IP KeepAliveTime Recommendation #12 Increase the Microsoft Initiator time-out value Recommendation #13 Specify automatic restoration of iscsi connections Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 11

12 Windows Servers Best Practices Recommendation #8 Disable client and services not required for iscsi on iscsi NICs For best performance, remove the Client for Microsoft Networks and File and Print Sharing for Microsoft Networks on iscsi network interface cards (NICs). Recommendation #9 Use the latest NIC driver NIC vendors frequently release new drivers that have enhancements and bug fixes. For best performance, install the latest vendor NIC driver on iscsi NICs. Recommendation #10 Install the latest Microsoft iscsi initiator Microsoft frequently releases new iscsi initiator versions that have enhancements and bug fixes. For best performance, install the latest Microsoft iscsi initiator on the Exchange Server. Recommendation #11 Modify the TCP/IP KeepAliveTime Denial-of-service (DoS) attacks are network attacks aimed at making a computer or a particular service on a computer unavailable to network users. The KeepAliveTime parameter controls how frequently TCP tries to verify that an idle connection is still intact by sending a keep-alive packet. Setting KeepAliveTime to 300,000 (5 minutes) hardens the TCP/IP attack against DoS attacks. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Par ameters\ KeepAliveTime = Dword: (decimal) For more information, please refer to Recommendation #12 Increase the Microsoft Initiator time-out value By default, the Microsoft iscsi initiator timeout is set to 60 seconds. This timeout defines how much time the initiator can hold a request before reporting an iscsi connection error. This value can be increased to accommodate longer outages, such as Data Mover cluster events. If an iscsi timeout occurs on an Exchange Server that hosts the Exchange database and transaction logs on iscsi LUNs, it will result in the database being unmounted. To change the time-out value, search the Windows Registry for the MaxRequestHoldTime entry under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet. 12 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

13 Windows Servers Best Practices Change the value to 600. The following is an example of the registry entry in one of the Exchange Servers: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E97B-E325-11CE-BFC BE10318}\0002\Parameters MaxRequestHoldTime = 600 (DWORD) Recommendation #13 Specify automatic restoration of iscsi connections When an Exchange Server is rebooted, the iscsi disks are not available unless the Automatically restore this connection when the system boots checkbox is selected. To ensure that the iscsi disks are available after a reboot, select the checkbox from the Log On to Target dialog box in the Microsoft iscsi initiator window as shown in Figure 1. Figure 1 Log On to Target dialog box with automatic restore option enabled Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 13

14 Windows Servers Best Practices 14 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

15 Chapter 3 Networking Best Practices This chapter presents these topics: Recommendation #14 Use GbE switches with VLAN capabilities Recommendation #15 Dedicate switches or VLANs Recommendation #16 Use GbE NICs on the Exchange Server Recommendation #17 Use CAT6 cables for Gigabit Ethernet connectivity Recommendation #18 Set the network speed and duplexing properly Recommendation #19 Specify the adapter binding order Recommendation #20 Disable DNS on the iscsi storage network Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 15

16 Networking Best Practices Recommendation #14 Use GbE switches with VLAN capabilities Use 1 Gb (GbE) switches that are capable of supporting virtual LANs (VLAN). This will allow the production and iscsi traffic to be segmented, resulting in best performance. Recommendation #15 Dedicate switches or VLANs When possible, use dedicated switches for production and iscsi traffic. If it is not possible to have dedicated switches, at a minimum ensure the switches are capable of creating VLANs to segment production and iscsi traffic. Recommendation #16 Use GbE NICs on the Exchange Server For best performance, use separate 1 Gigabit Ethernet (GbE) network interface cards (NICs) for production network traffic and iscsi network traffic. EMC recommends having one NIC for production network traffic and one or more NICs for iscsi network traffic. Recommendation #17 Use CAT6 cables for Gigabit Ethernet connectivity CAT6 cables demonstrate a dramatic improvement for gigabit connectivity over CAT5E cables. To ensure the best performance and reliability between Exchange Server and Celerra iscsi LUNs, EMC recommends using CAT6 cables. Recommendation #18 Set the network speed and duplexing properly Once the setup is completed and it has been verified that the infrastructure supports GbE properly, then the switch ports and NIC ports should be configured to 1Gbps and FULL duplex. During setup it may be necessary to use AUTO settings to ensure that everything works properly in a new environment; however, the proper speed and duplex settings should be set explicitly in production systems for certain NIC cards. Recommendation #19 Specify the adapter binding order Exchange Servers rely heavily on the Active Directory and Global Catalog servers. Exchange Servers that have multiple network adapters for public, cluster heartbeat, and iscsi traffic may have connection difficulties in connecting to the Active Directory if the public network card is not set to the top of the adapter binding order list. Therefore, EMC recommends placing the public network adapters on top of the adapter binding order. Recommendation #20 Disable DNS on the iscsi storage network Exchange Servers do not require DNS service on their iscsi storage network. Further, operational conflicts can occur if DNS service is not configured properly. For these reasons, disabling DNS service on the iscsi storage network is recommended. 16 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

17 Chapter 4 Backup, Restore, and Replication Best Practices This chapter presents these topics: Recommendation #21 Use a deduplication appliance Recommendation #22 Use the Data Protection Manager Recommendation #23 Use RM for Celerra and VSS Recommendation #24 Schedule RM VSS snapshots appropriately Recommendation #25 Use two iscsi LUNs per Exchange storage group Recommendation #26 Create multiple Exchange storage groups Recommendation #27 Use the EMC NetWorker Module for Exchange Recommendation #28 Use Exchange Continuous Replication features appropriately Recommendation #29 Use Automatic Volume Management Recommendation #30 Separate active storage from passive storage Recommendation #31 Plan for Microsoft Exchange continuous replication I/O levels Recommendation #32 Use scripts for crash consistent replication in CLI mode Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 17

18 Backup, Restore, and Replication Best Practices Recommendation #21 Use a deduplication appliance A deduplication appliance significantly reduces the backup space with the deduplication technology. When a deduplication appliance sees a repeated block of data in the backup, it stores a pointer instead of storing the block again. Since an Exchange backup commonly has multiple duplicate s across mailboxes, the use of a deduplication appliance significantly reduces backup space. Therefore it is recommended to use a deduplication appliance for Exchange backup. Recommendation #22 Use the Data Protection Manager 2007 Microsoft created a storage calculator for DPM backup calculation according to customer usage. It calculated the appropriate required backup storage according to the read/write ratio, network rate, and backup/restore/retention frequency. It is recommended to use Microsoft s DPM storage calculator to size the backup space when sizing the DPM backup storage. The DPM storage calculator can be found in the following link: Recommendation #23 Use RM for Celerra and VSS EMC Replication Manager (RM) for Celerra has the ability to create point-in-time replicas of databases and file systems residing on Celerra iscsi virtual LUNs, allowing some recovery scenarios to bypass the need for loading data from tape. Some of the benefits of using RM for Celerra to back up Exchange 2007 are as follows: Quick backup and restore. RM takes only a few minutes to back up or restore an Exchange storage group. Ease of use. RM has a simple interface with which an IT administrator can discover applications, select Exchange storage groups, and execute backup or restore operations. Integrated with Microsoft Volume Shadow Copy Services (VSS). RM is integrated with the Microsoft VSS architecture when running Exchange 2007 on Windows Server For more on the VSS framework, and how it is used to guarantee database consistency when snapping Microsoft Server 2003 applications, refer to the Exchange Server 2003 data backup and Volume Shadow Copy services article on the Microsoft website. Multiple backups. RM can allow for up to 1,000 snaps of an Exchange storage group. This can provide freedom to use tape backups less frequently, while maintaining more point-intime copies on Celerra systems for immediate restore. Option to truncate transaction logs. RM has the option of truncating the transaction logs during backup. This allows an IT administrator to have full, incremental, and differential backup operations using RM. Checks database integrity for every backup. RM checks the Exchange database integrity using the Microsoft ESEUTIL tool for every backup. 18 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

19 Backup, Restore, and Replication Best Practices Integrates with your tape backup software. RM integrates with the existing tape backup software, so it can instantly snap the Exchange Server and then mount the snapshot to an alternate host to stream to tape. This means that you can maintain your existing tape if you desire offsite copies, but you may never require a restore from tape. In addition, RM has an option to run any scripts to execute jobs before and after the replication. When RM is used for backup, it has the following effect on performance: Increase in write latency. The database write latency will increase but is still well below the Microsoft recommended log and database latency values for good performance. Decrease in user space on the Exchange database file system. Since RM stores backups on the same file system as the production iscsi LUN, storage requirements for a given number of users depend on the number of backup snaps an Exchange administrator wants to keep. This concept of space reservation is common to most snapshot implementations and is designed to ensure that snapshots always have sufficient space to complete, and the worstcase restore scenarios can complete successfully. Sizing Considerations for iscsi Replication on EMC Celerra Technical Note provides more information about iscsi snap and replication sizing and other storage considerations. Recommendation #24 Schedule RM VSS snapshots appropriately Complete verification (using ESEUTIL /K) of the VSS snapshots is enforced by RM and is required by Microsoft. Snapshots of iscsi LUNs do not place a significant load on the production system when it is in a steady state. However, there is a momentary (measured in seconds) impact when the snapshot is taken. ESEUTIL verification of a snapshot can impact the production environment (since the iscsi LUN snapshot is largely made up of the same physical data as the production iscsi LUN). This large verification load can be expected to last roughly two hours for a 150 GB database. Due to this mandatory verification, we suggest that you not take snapshots during production periods. Recommendation #25 Use two iscsi LUNs per Exchange storage group When Celerra iscsi takes a snap of the storage group, it takes a point-in-time copy of all the underlining iscsi LUNs related to that particular storage group. Therefore it is recommended to have two dedicated iscsi LUNs per storage group (one for the database and one for the log of that storage group) to have independent backup schedules. Recommendation #26 Create multiple Exchange storage groups A small number of mailboxes with multiple mailbox stores facilitate quick backup and recovery, as well as minimal mailbox disruption if data corruption occurs. Also, more storage group allows for Exchange mailboxes to have more cache buffers per mailbox user. This will reduce IO operation on the mailbox server. Recommendation #27 Use the EMC NetWorker Module for Exchange EMC NetWorker Module for Microsoft Exchange Server has been tested and validated to back up and restore Microsoft Exchange Server 2007 on Celerra with ATA drives. Therefore, use EMC NetWorker Module for Microsoft Exchange Server along with Celerra if a backup-to-disk solution is desired for the Exchange environment. Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 19

20 Backup, Restore, and Replication Best Practices Recommendation #28 Use Exchange Continuous Replication features appropriately Microsoft has three built-in continuous replication features in Exchange Each feature serves a different purpose in the Exchange environment. Local Continuous Replication (LCR) is designed to have a redundant copy of the Exchange production data on the same Exchange Server. Use LCR for a quick manual switchover to a secondary copy of the Exchange data in case of corruption of the production data. Cluster Continuous Replication (CCR) uses log shipping and replay technology to create and maintain a redundant copy of the Exchange data on another server. It utilizes Microsoft Cluster Service along with the redundant copy of the Exchange data to provide automatic failover solutions. Use CCR for high availability in the data center. Standby Continuous Replication (SCR) utilizes log shipping and replay technology to create additional storage group copies to another Exchange Server. Use SCR for site resiliency and high availability. Recommendation #29 Use Automatic Volume Management The Automatic Volume Management (AVM) feature of the Celerra Network Server automates volume creation and management. AVM system-defined pools provide a simple way to create and manage file systems through automatic creation and management of volumes. This eliminates the need to manually create stripes, slices, or metavolumes, while supporting high availability and best performance considerations. For best performance, use AVM with the clar_ata system defined storage pool to create the streaming backup file systems on ATA drives. Recommendation #30 Separate active storage from passive storage It is important to separate the active storage spindles from the passive storage spindles for storage resiliency in the LCR configuration because a disk failure will affect both the active and passive copy of the Exchange storage. Recommendation #31 Plan for Microsoft Exchange continuous replication I/O levels The method continuous replication (LCR or CCR) uses to commit transactions at the target site causes two to three times more I/O than on the source site (with the RTM version). Therefore, it is important to provision the target continuous replication storage to handle up to three times the source storage IOPs. Note: For step-by-step instructions for creating file systems and iscsi LUNs on a Celerra for target continuous replication storage, please refer to EMC Solutions for Microsoft Exchange 2007 EMC Celerra NS Series Destination for Local Continuous Replication Configuration Build Document. This is an internal-only document available to EMC employees and partners on Powerlink. 20 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

21 Backup, Restore, and Replication Best Practices Recommendation #32 Use scripts for crash consistent replication in CLI mode Tests have shown that an Exchange database is crash consistent when the snaps of the database and log iscsi LUNs were taken in quick succession. Hence, it is recommended to use scripts to execute Replicator CLI commands in quick succession. Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 21

22 Backup, Restore, and Replication Best Practices 22 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

23 Chapter 5 Storage Best Practices This chapter presents these topics: Recommendation #33 Use DISKPAR/DISKPART to align the NTFS volume Recommendation #34 Set the LUN NTFS allocation unit Recommendation #35 Plan storage layout for performance, not capacity Recommendation #36 Use the building block approach to allocate spindles Recommendation #37 Do not exceed 80% utilization of LUNs Recommendation #38 Use Multiple Connections per Session (MC/S) Recommendation #39 Use dedicated Celerra file systems Recommendation #40 Use high rpm disk drives Recommendation #41 Use RAID 1 for log files Recommendation #42 Use RAID 1 with striping for database files Recommendation #43 Use the latest Celerra software Recommendation #44 Fail over Data Movers before rebooting Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 23

24 Storage Best Practices Recommendation #33 Use DISKPAR/DISKPART to align the NTFS volume This is the most critical recommendation among all the other recommendations. When Microsoft (Windows Server 2000/2003) Disk Manager formats the Celerra iscsi LUNs, it always creates the partition starting at the 64th sector, thereby misaligning it with the underlying physical disk. Due to this misalignment, Exchange I/O that would have fit evenly on the disks may result in more than one I/O to the physical disk drive. To fix the disk alignment, Microsoft provides a command line tool DISKPAR.exe. DISKPAR.exe comes with the Windows 2000 Resource Kit and it can explicitly set the starting offset in the master boot record (MBR). This utility is merged with DISKPART.exe on Windows Server 2003 Service Pack 1 Support Tools. Use DISKPAR to set the offset to 128 sectors or use DISKPART to set the offset to 64 KB. This disk alignment technique increases the Exchange I/O performance significantly (up to 65 percent) on Celerra iscsi LUNs. The following example uses DISKPART against drive 4. C:\>Diskpart Microsoft DiskPart version Copyright (C) Microsoft Corporation. On computer: JC27Q91X32 DISKPART> list disk Disk ### Status Size Free Dyn Gpt Disk 1 Online 136 GB 112 GB Disk 2 Online 267 GB 0 B Disk 3 Online 267 GB 0 B Disk 4 Online 600 GB 600 GB DISKPART> select disk 4 Disk 4 is now the selected disk. DISKPART> create partition primary align=64 DISKPART succeeded in creating the specified partition. Using the Microsoft Disk Manager select the Drive Letter or Mount Point to be associated with the corresponding LUN. 24 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

25 Storage Best Practices Recommendation #34 Set the LUN NTFS allocation unit When formatting a new drive using Disk Administrator, the allocation unit size, or block size, chosen will affect application performance. For Microsoft Exchange Server 2007, Microsoft recommends using a 64k block size. This recommendation helps to improve performance in streaming backup and eseutil tasks that are sequential read operations. Recommendation #35 Plan storage layout for performance, not capacity The most common error made when planning an Exchange Server deployment is designing for capacity and not for performance or IOPS (I/O per second). The most important single storage parameter for performance is disk latency. High disk latency is synonymous with slower performance. Microsoft guidelines for good performance are as follows: Average database read and write latencies below 20 ms Maximum database read and write latency below 50 ms Average log write latencies below 10 ms In today s disk technology, the increase in storage capacity of a disk drive has outpaced the increase in IOPS. Therefore, the IOPS capacity is the standard to use when planning Exchange storage configurations. Recommendation #36 Use the building block approach to allocate spindles This Exchange 2007 building block is defined as two log spindles and four database spindles. Please refer to the ESRP results at the Microsoft website ( for performance and storage considerations of the building block configuration. Note: For step-by-step instructions for creating file systems and iscsi LUNs on a Celerra for Exchange 2007, please refer to EMC Solutions for Microsoft Exchange 2007 EMC Celerra NS Series Configuration Build Document. This is an internal-only document available to EMC employees and partners on Powerlink. Recommendation #37 Do not exceed 80% utilization of LUNs For the best performance, the utilized drive (NTFS formatted) capacity must not exceed 80 percent. There will be performance bottlenecks if this threshold is exceeded. This is because NTFS needs additional space to work efficiently. If the space is not available, NTFS cannot function to its full potential and performance can degrade. This can, in turn, cause excessive disk fragmentation, which can add to the performance degradation. Following this recommendation will also provide you with some protection against application failure if there is unexpected growth in your database. Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 25

26 Storage Best Practices Recommendation #38 Use Multiple Connections per Session (MC/S) According to Microsoft, when a target supports Multiple Connections per Session (MC/S), as Celerra does, and the Microsoft iscsi Initiator is being used, Microsoft recommends using MC/S instead of MPIO. The solution was validated with Microsoft iscsi Software Initiator 2.04 using MC/S in Round Robin mode. Please check the E-Lab Interoperability Navigator for the latest supported version of the Microsoft iscsi initiator. Note: For more information, refer to the Microsoft iscsi Software Initiator User's Guide. Recommendation #39 Use dedicated Celerra file systems Use file systems created for Microsoft Exchange Server 2007 operations only for those operations and not for any other I/O operations. This ensures more predictable performance from Microsoft Exchange Server Recommendation #40 Use high rpm disk drives High rpm drives provide higher overall random access throughput and shorter response times than slower rpm drives. For optimum performance, higher rpm drives are recommended. Recommendation #41 Use RAID 1 for log files For highest fault tolerance and best performance, use EMC RAID 1 starting with two drives and expanding as required. Recommendation #42 Use RAID 1 with striping for database files RAID 1 with striping outperforms RAID 5 in random read/write and rebuilding time. Also the write penalty for RAID 5 is too high for Exchange 2007 database I/O since the read-to-write ratio is 1:1. Therefore, RAID 1 with striping is recommended for best performance and the highest fault tolerance for Microsoft Exchange databases. However RAID 5 is recommended for large mailbox configuration. Recommendation #43 Use the latest Celerra software Install the latest available Celerra release code or patch to take advantage of new features, functionality, and bug fixes. Refer to the most recent Celerra release notes for detailed information. Recommendation #44 Fail over Data Movers before rebooting The primary Data Mover will automatically fail over to the standby Data Mover if the primary Data Mover panics or fails. However, the primary Data Mover will not automatically fail over if it is rebooted. Therefore, before rebooting the primary Data Mover, manually fail over to the standby Data Mover and make sure the Exchange database is operating properly; then reboot the primary Data Mover and perform a failback operation. Similarly, fail over to the standby Data Mover prior to performing any maintenance on the primary Data Mover. 26 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

27 Chapter 6 Archiving Best Practices This chapter presents these topics: Recommendation #45 Use EMC Xtender Recommendation #46 Use the File Level Retention (FLR) toolkit Recommendation #47 Use the Celerra WORM file system Recommendation #48 Use FC drives for Journaling folders Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 27

28 Archiving Best Practices Recommendation #45 Use EMC SourceOne / Xtender EMC SourceOne/ Xtender provides a centrally managed archiving solution for compliance and legal risk issues in the messaging environment. SourceOne/ Xtender can be rapidly deployed into an existing Microsoft Exchange environment to reduce storage costs and improve search and recovery. Therefore, use SourceOne/ Xtender for an archiving solution. Recommendation #46 Use the File Level Retention (FLR) toolkit When Xtender creates the archive files and placed it on the CWORM file system, the retention period is infinite. Therefore an administrator needs to manually change the WORM state in order to purge the archived s. FLR toolkit provides the ability to set and expire the retention on the archived s without any intervention by the administrator. Recommendation #47 Use the Celerra WORM file system Celerra has a built-in feature that creates Write Once Read Many (WORM) file systems on standard disks. The Celerra WORM feature prevents any files from being modified or deleted by other clients and users. Therefore, a Celerra WORM file system is an ideal place to store archived s. Recommendation #48 Use High IO throughput drives for Journaling folders During archiving, the Microsoft message queue (MSMQ), Xtender message center, and Xtender journaling are heavily utilized. Therefore it is highly recommended to move them to high performance drives for better performance. 28 Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms

29 Chapter 7 Virtual Infrastructure Best Practices This chapter presents these topics: Recommendation #49 Use VMware vcenter Server Recommendation #50 Make the VMware vcenter Server highly available Recommendation #51 Use uncached mode Recommendation #52 Be aware of virtual machine time considerations Conclusion Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms 29

30 Virtual Infrastructure Best Practices Recommendation #49 Use VMware vcenter Server In a VMware virtual environment, the management of the virtual data center is made easy through the use of vcenter Server. vcenter Server is important for the proper functioning of several VM features such as VMHA, DRS, and VMotion. Also, vcenter Server adds ease of use to all of the following features: VM Template creation and deployment throughout the data center Historical and realtime performance tracking of ESX hosts and VMs Tracking of VM to host mapping Initialization of new storage, including alignment of VMware vstorage VMFS volumes Recommendation #50 Make the VMware vcenter Server highly available In a VMware virtual environment, the most critical piece of any VMware ESX implementation is a combination of the vcenter Server and the license server (together referred to as the VC Server). Without these two components, which are usually installed on the same host, it is possible to lose much of ESX s functionality, including the ability to do things like DRS, VMHA, VMotion, and/or simply starting a VM. Therefore, it is important that the vcenter Server be highly available. The easiest and most reliable way to accomplish this is to run the vcenter Server on physical machines in an MSCS cluster. It is also critical that the Microsoft SQL Server database that vcenter Server uses be implemented in a highly available fashion. Recommendation #51 Use uncached mode If you are using VMware ESX server or a Microsoft Hyper-V server to host Exchange Server, then you have the option of creating an NFS data store on the Celerra instead of a traditional iscsi LUN. When mounting the NFS file system on the Celerra Data Mover you should add the following flag: -option uncached. Testing has shown that under most loads the uncached option yields substantial performance benefits. Recommendation #52 Be aware of virtual machine time considerations Because virtual machines work by time-sharing host physical hardware, a virtual machine cannot duplicate the timing behavior of a physical machine. This can impact the virtual machine operating system in numerous ways. As a best practice, refer to all the relevant documentation from your Hypervisor provider to understand how it can impact your environment. For example, VMware has a guide on timekeeping called Timekeeping in VMware Virtual Machines available at: Conclusion EMC recommends applying all best practice guidelines in the Exchange Server 2007 environment to have a consolidated Microsoft Exchange infrastructure. These best practices enable customers to optimize their environment for performance, scalability, and disaster recoverability with EMC Celerra NS40 and Microsoft Exchange Microsoft Exchange 2007 EMC Celerra Unified Storage Platforms