Apple Xsan 1.4 User Manual
Page 43
Chapter 2
Setting Up a Storage Area Network
43
 Use a router to isolate the Ethernet network used by the SAN from a company
intranet or the Internet, or better, use a second Ethernet network (including a second
Ethernet card in each SAN computer) for the SAN.
 If your SAN uses directory services, mail services, or other services on a separate
server, use a second, separate Ethernet network to connect SAN computers to that
server.
 As a rule of thumb, consider that a single Xserve RAID controller, after file system
overhead, can transfer roughly 80 MB of user data per second (160 MB per Xserve
RAID system). If your SAN must support an application running on multiple clients
that requires specific throughput on each client, you can use this number to estimate
the number of Xserve RAID systems necessary to support the aggregate transfer rate.
Availability Considerations
If high availability is important for your data, set up at least one standby controller in
addition to your primary controller. Also, consider setting up dual Fibre Channel
connections between each client, controller, and storage device using redundant Fibre
Channel switches.
Important:
Losing a metadata controller without a standby can result in the loss of all
data on a volume. A standby controller is recommended.
Also, if you have a standby controller, you can upgrade the Xsan software without
interrupting the SAN. For more information, see “Upgrading Controller Software” on