HP StorageWorks 4000/6000/8000 .HP StorageWorks SAN Design Reference Guide, Pa - Page 392

Designing a Microsoft Exchange solution with iSCSI Feature Pack A Microsoft Exchange solution requires that you configure the network, host, and storage systems for iSCSI NAS. The HP ProLiant Storage Server iSCSI Feature Pack provides iSCSI functionality on a Windows Storage Server (NAS device). Exchange Server 2003 also requires an iSCSI initiator. Network design Existing IP networks may not be suitable for iSCSI storage support. Evaluate traffic on these networks to determine if there is adequate capacity to meet storage requirements. HP recommends a dedicated GbE network for accessing the Windows iSCSI NAS Storage Server. This provides adequate performance and data security. You can also use IPsec to secure the connection on a public, unsecured network, with decreased performance. The distance between the Exchange server and the iSCSI NAS Storage Server may affect performance. You must check the maximum supported distances of the network devices. The maximum distance varies based on the cable type and specifications. Hardware selection The Windows Server Catalog is available at http://www.microsoft.com/windows/catalog/server/default.aspx?subID=22&xslt=about&pgn= moreinfo. It lists iSCSI hardware components that are qualified under the Designed for Windows Logo program, Exchange Server 2003 and Exchange Server 2000. Exchange storage design Important criteria for Exchange storage design include: • Isolation of Exchange transaction logs from databases • Selection of optimum RAID level for performance and fault tolerance • Write-back caching for hardware RAID controller performance Separate volumes for logs and databases HP recommends separate volumes for Exchange transaction logs and databases, to ensure data protection and efficiency. Transaction log access is mostly sequential writes does database access is random read/write. The Exchange server internal storage can hold the Exchange transaction logs while the HP Storage Server with the HP iSCSI Feature Pack holds the Exchange databases. The Exchange server internal storage and the iSCSI NAS Storage Server have comparable transaction log performance. If the transaction logs are stored on the Exchange server, you must recover them manually if the server fails. Regaining access to the log drives requires installing the logs on a backup Exchange server. NOTE: Store transaction logs on a RAID 1 mirror pair array volume, or, for additional disk space, on four or more disks on a RAID 1+0 (striped mirror). 392 iSCSI storage