Best Practices for Configuring and Using the SAN
If you have two partner storage servers in a high load environments, you may wish to incorporate some of the practices outlined below to optimize the performance of your SAN, as well as the management of your SAN in the event of failure, or when upgrading or modifying your configuration.
Environment
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Your storage servers should be dedicated to only running SANmelody software. Do not use them for any other purpose.
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If using storage server partners for high availability, design your SAN network so that all storage devices (physical storage, storage servers, switch fabrics) allow for the shutdown of a complete storage path from application server through physical disk without impacting other paths. This allows for the event (upgrade, failure, addition, and so forth) to occur with minimal impact.
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Label cables and host bus adapters (HBAs).
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Separation of components leads to a higher degree of availability because they are not in the same environment.
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Keep storage servers out of the public network.
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Separate servers from storage racks.
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Keep switches in separate racks.
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Do not take power from the same grid (if possible).
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Hardware Configuration
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Calculate I/Ops required by the application server layer and then decide on the number of application server ports to use. Alternatively, the following handles average traffic:
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Two storage server target-only ports
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Two unidirectional dedicated mirror ports
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Two storage server initiator ports
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Physical storage performance is a key factor to overall system performance, particularly in high load environments.
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DataCore storage servers implement a RAID1 mirror when synchronous (secondary) mirroring is used with multipathing.
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Application vendors’ recommendations for separate disks translates directly to separate pools for virtual disk sources.
High Availability Configuration
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Use LUN distribution if your storage controller supports an active/active configuration. LUN distribution requires TRUE active/active functionality from the storage subsystem with multiple controllers.
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If you intend on setting up the Windows application server for HA using MPIO, then install MPIO before mapping third party AP volumes to the application server.
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Paths from each application server to each storage server should be physically independent. This means physically separating switches for Fibre Channel (FC) and independent subnets and switches for iSCSI provide the highest level of availability.
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If using iSCSI. refer to Best Practices for iSCSI High Availability.
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If mapping the same virtual volume to multiple application servers, refer to LUN Numbering Consistency.
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