.SAN design reference guide Vol. 1-5 785350-001

calculated from the average I/O needs an additional safety factor to maintain performance during
peak periods.
In practice, the maximum number of users is less than the calculated value when:
• Users increase the size of their mailboxes.
• Services such as antivirus scanners or content indexers are added to the Exchange server.
A medium-sized user profile provides a 60 MB mailbox, and a large profile provides a 100 MB
mailbox. Larger mailboxes affect both storage sizing and performance, and are disproportionately
more difficult for Exchange to manage.
Sample iSCSI NAS Microsoft Exchange Server 2003 configuration
This section summarizes results from an HP-tested iSCSI NAS configuration. Details of this test are
available at http://storage.corp.hp.com/Document_Storage/whitepapers/new_library/
5982-9399EN_Exchange_2003_HP_iSCSI_and_WSS_NAS_WP.pdf.
HP ProLiant DL380 G4 Storage Server configuration
With up to six internal drives and fault-tolerant options for fans and power supplies, an HP ProLiant
DL380 server acts as a high-capacity Exchange server. Other HP ProLiant servers can support 900
to 2,000 Exchange mailboxes.
When configuring the server and storage, ensure that you have:
• Sufficient RAM (1 GB) on the server.
• Enough disks for the Exchange database volume, especially if you use RAID 5 RAIDsets or
ADG. A larger number of disks improves database volume performance.
The Exchange server internal RAID storage holds the transaction logs. HP recommends storing the
transaction logs on a RAID array accelerated with a write-back cache, with battery backup. The
transaction logs can be stored on an iSCSI NAS RAID array.
For the sample configuration, the server includes a Smart Array 5i RAID controller option kit since
the write cache for this controller can be set at 100%, increasing performance.
RAID 1+0 is preferred for the database volume on the storage server. In the sample iSCSI NAS
storage configuration:
• The DL380 G4 Storage Server uses a Smart Array 6402 and Smart Array 6404 controller to
access the disks for its RAID array.
• 56 disks are available for RAID configurations. These disks sit in four rack-mountable HP
StorageWorks Modular Smart Array 30 (MSA30) disk enclosures with 14 drives each.
• A 40-disk RAID 1+0 configuration consists of an array of 10 disks in each of the four
enclosures.
The Exchange server accesses its database on the iSCSI NAS RAID 1+0 volume.
364 iSCSI storage