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.
In this example, we are using the most basic of topologies. We have a total of 3.9 TBs of storage utilizing a fully populated RAID. The SANs bandwidth availability with one fully populated Xserve RAID is 160–200 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 setup 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 5.6TB (fully populated with 400GB Drive Modules)
512MB 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
1GB 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-X card
Mac OS X v10.3.6 or later
Apple Xsan software
In this larger implementation, we have six clients accessing a total of 7.9 TB of storage. The SANs bandwidth availability with two fully populated Xserve RAIDs is 320–400 MB/s. This SAN is connected to an outer network, shown in green. Notice that all trivial Ethernet components are routed to this outer network, and only the nodes of the SAN are on the metadata network. Further, we have a standby metadata controller available to take over MDC duties if the primary MDC fails. For directory services, we have three choices:
The primary MDC is the open directory master of the SAN, with the standby MDC as a replica.
The standby MDC is the open directory master of the SAN, with the primary MDC as the replica.
The directory has been moved to the outer network, thereby allowing the Xserve units to just be MDCs (recommended).
Storage
2 x Xserve RAID 5.6TB (fully populated with 400GB Drive Modules)
512MB 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
1GB 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-X card
Apple Ethernet PCI-X card
Mac OS X v10.3.6 or later
Apple Xsan software
Outer Network
Mac OS X Server running Open Directory to provide directory services, or a system running a similar service such as Active Directory.
In this topology, ten clients share 15.9 TB of storage. The SAN’s bandwidth availability with four fully populated Xserve RAIDs is a whopping 640–800 MBs. Because of the number of Fibre cables in this topology (32 total), an additional switch has been implemented. Data cascades effortlessly between the two switches because a high-bandwidth inter-switch link (ISL) has been made with six user ports on each switch. Think of it as a data river that flows bidirectionally between each switch. A primary and a standby MDC are mandatory with such a large implementation. To keep their roles simple and efficient, the directory is implemented on the outer network.
Storage
4 x Xserve RAID 5.6TB (fully populated with 400GB Drive Modules)
512MB 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
1GB 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)
Ethernet Switch (Metadata network)
1 x unmanaged Ethernet Gigabit switch
Client Workstations
Power Macintosh G5 or Power Macintosh G4 Dual 800 or faster
Apple Fibre Channel PCI-X card
Apple Ethernet PCI-X card
Mac OS X v10.3.6 or later
Apple Xsan software
Outer Network
Mac OS X Server running Open Directory to provide directory services, or a system running a similar service such as Active Directory.