Fibre Channel Switches

Much like Ethernet switches, Fibre Channel switches must be used to connect all of your clients , controllers, and storage together. There are many types of Fibre Channel switches, and Apple has tested and approved a few of them for use with Xsan:

• Brocade SilkWorm 3200, 3250, 3800, 3850, 3900, and 12000 series

• QLogic SANbox 2-8, SANbox 2-16, SANbox 2-64, SANbox 5200, and SANbox 5202

• Emulex SAN Switch 355, 375, and 9200

• Cisco MDS 9120, 9140, 9216, 9506, and 9509

Each of these switches must be configured as open fabric, where each port sees every other port. In general, the default configuration of these switches will work with Xsan. If you need to reconfigure or verify the switch settings, you need to connect to the switch with your Macintosh via an Ethernet connection. From there, you can run either a standard browser to view the switch configuration or specialized Java applications built specifically for switch setup.

See Lesson 7 for more information on switch setup.

Metadata Network

Regardless of the size of your SAN implementation, you will also need another out-of- band network, which means that although the clients are connected to the rest of the SAN through Fibre Channel connections, the metadata and file access communication travel on a separate Ethernet network. Splitting the connection into two independent networks ensures that no "non-metadata" data packets clog up the Fibre Channel network, giving you the maximum bandwidth for large data files.

Needless to say, both a Fibre Channel switch and an Ethernet switch (1000 Base-T recommended, also known as Gigabit Ethernet) are necessary to configure Xsan. It is also desirable to keep the "chatter" separate from the out-of-band network by connecting clients to the Internet using a secondary Ethernet port. If your computer has only one Ethernet port and you want access to a network outside your SAN, you can place an additional Ethernet PCI card in your client computers.

Lesson 3. Xsan Topologies

There are numerous ways for you to implement your new SAN. The following three examples show typical topologies for production environments. Again, these are guides, intended to provide a summary of the previously discussed information as you plan and acquire your equipment for integration.

Topology Example 1

In this example, we are using the most basic of topologies. We have a total of 3.9 TB of storage utilizing a fully populated RAID (5.6 TB model). The SAN's bandwidth availability with one fully populated Xserve RAID is 160 to 200 megabytes per second (MB/s). This SAN is isolated; that is, the system is not connected to an outer network. This is perfect for implementations in which highly confidential content is being edited. Also, we are not utilizing a centralized directory, so clients will be locally authenticated (the server will not be in control of the login process), and the "chatter" on the metadata network will be kept to a minimum. In order to access and set up either the Fibre Channel switch or the Xserve RAID, an additional connection must be made from a separate computer outside the network.

Storage

• 1 x Xserve RAID 5.6 TB (fully populated with 400 GB drive modules)

• 512 MB cache per controller (1 GB total)

Fibre Channel Switch

• 1 x Apple qualified Fibre Channel switch

Metadata Controllers

• Xserve, Xserve G5, or Xserve G5 cluster node

• 1 GB RAM per controller

• Apple Fibre Channel PCI-X card

• Mac OS X Server v10.3.6 or later

• Apple Xsan software

• PCI video card (optional)

Metadata Network

• 1 x unmanaged gigabit Ethernet switch

Client Workstations

• Power Macintosh G5 or Power Macintosh G4 Dual 800 or faster

• Apple Fibre Channel PCI Express or PCI-X card

• Mac OS X v10.3.6 or later

• Apple Xsan software