Microsoft KB Archive/317162

= Supported Fibre Channel configurations =

Article ID: 317162

Article Last Modified on 3/1/2007

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APPLIES TO


 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Datacenter Server

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This article was previously published under Q317162





SUMMARY
This article lists supported Fibre Channel storage configurations that you can use when you configure your servers. Because there are many different options available for setting up and configuring a Fibre Channel storage configuration, you can use this article as a guide when you consider different configurations that involve Windows server operating systems.



Recommended and Supported Configurations

 * You can use any single computer that is connected to its dedicated storage through any topology (point-to-point, FC-PLDA or FC-FLA, FC-PLA, or Fabric).
 * You can use multiple computers (cluster computers, isolated computers, or both) on a Fibre Channel system that uses point-to point Fabric or point-to-point FC-AL connections only. It is a good idea to use zoning because each cluster or isolated computer and its storage devices must be isolated. Some storage vendors include LUN masking features (this is sometimes called selective presentation) that you can also use to isolate computers.
 * You can use loop attachment for two-node clusters, provided that only one cluster and its storage are attached on each hub or dynamic point-to-point FC-AL switch; use of partitioned hubs or zoning on these devices will allow more than one two-node cluster, provided that each cluster and its storage are completely isolated (for example, no LIP propagation) from any other cluster or computer system.
 * You can attach a single loop-only storage device to an FL_Port on a Fabric switch, even if multiple hosts are present on other switch ports, but you must configure all of the hosts for a Fabric connection (point-to-point as N_Ports). FC-AL switches must have active LIP isolation systems, zoning, or both in place to control the propagation of LIPs such that hosts are protected from the LIPs of other hosts.
 * If you use a partitionable or zoning hub, you can treat this configuration as if multiple hubs were available. Only a single computer and its dedicated storage can be connected to each partition.

Unsupported Configurations

 * You cannot use multiple computers (cluster computers, isolated computers, or both) that are connected to the same storage devices by using loop topologies (FC-PLDA, FC-AL, FC-FLA or FC-PLA) except as noted earlier for two-node clusters, partitioned/zoning hubs, FC-AL switches with active LIP isolation systems. Even when LUN masking is employed at the storage, there is not sufficient isolation between unclustered systems to allow for reliable operation of multiple computers in the same partition and zone.
 * Clusters with more than two nodes are not supported with Fibre Channel loop configurations. Datacenter clusters do not support Fibre Channel loops for any configurations, except as noted earlier for FC-AL switches with active LIP isolation in place, zoning systems in place, or both.

Multiported Devices
Depending on the storage, you can treat each port as a separate device attachment. For example, an EMC Symmetrix device with 32 ports can have 32 computers directly attached (one to each port). Dual-loop JBOD devices are not multiport devices for the purpose of this article.

FC-AL technology is fully supported with Windows server operating systems, but there are differences in topologies that make loops less useful, and that may cause problems. If there are only two endpoints in your configuration (a server and a dedicated storage unit [JBOD] for that server), any topology is supported. If you are using a hub or loop switch with no active LIP isolation, with no zoning capabilities, or both to connect additional servers or storage. These problems include:  • Devices or computers that enter a loop cause Loop Initialization Primitives (LIPs). LIPs are presented to the operating system as bus resets, causing time-outs or possible data loss, and may cause computers to stop responding (hang). A device is recognized as entering the loop when you turn the device on, reboot it, or physically plug it into the loop. When a LIP takes place, system stability and data integrity are jeopardized. This applies to any of the servers on the loop. FC-AL switches with active LIP isolation systems, zoning, or both control how LIPs are propagated in storage systems and eliminate these initialization problems. Microsoft does not support operating system paging file on loops for the reasons that are described in the preceding item. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

305547 Support for booting from a Storage Area Network (SAN)

 Monolithic Fibre Channel HBA drivers are not designed for the Microsoft implementation of Multi-Path I/O. Therefore, any testing is limited to that which an IHV can provide. Additionally, because Microsoft does not test monolithic drivers, and because the value-added features that an IHV may include, beyond what is included in the HCT, issues that are exposed in the operating system from customer use may not be fixable.

Relying on only Change Control practices to prevent incorrect uses of loop topologies with clusters, groups of computers, and SANs does not prevent all possible problems that are related to these implementations. Therefore, the Microsoft policies and recommendations for loop solutions with no active LIP isolation capabilities include:
 * Microsoft strongly recommends using Fibre Channel Fabric switch or FC-AL switch with active LIP Isolation implementations and configurations instead of loops.

Definitions

 * FC-AL: Fibre Channel Arbitrated Loop
 * FC-FLA: Fibre Channel Fabric Loop Attachment
 * FC-PLA: Fibre Channel Private Loop Attachment
 * FC-PLDA: Fibre Channel Private Loop SCSI Direct Attachment
 * FL_Port: Fabric Loop Port
 * JBOD: Just a Bunch of Disks
 * IHV: Independent Hardware Vendor
 * HCT: Hardware Compatibility Test

For more information about SAN configurations, click the following article numbers to view the articles in the Microsoft Knowledge Base:

305547 Support for booting from a Storage Area Network (SAN)

310072 Adding support for more than eight LUNs in Windows Server 2003 and in Windows 2000

Keywords: kbenv kbinfo kbnetwork KB317162

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