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•Number of shared SCSI buses and the storage on each shared bus
Using shared SCSI buses increases storage availability. You can connect 32 shared SCSI buses to a cluster member. You can use any combination of
In addition, RAID array controllers allow you to increase your storage capacity and protect against disk, controller, host bus adapter, and SCSI bus failures. Mirroring data across shared buses provides you with more reliable and available data. You can use Logical Storage Manager (LSM)
•No
You can use mirroring and
•Tape loaders on a shared SCSI bus
Because of the length of the internal SCSI cables in some tape loaders (up to 3 meters), they cannot be externally terminated with a trilink/terminator combination. Therefore, in general, with the exception of the TL890, TL891, and TL892, tape loaders must be on the end of the shared SCSI bus. See Chapter 8 for information on configuring tape devices on a shared SCSI bus.
•You cannot use Prestoserve in a TruCluster Server cluster to cache I/O operations for any storage device, regardless of whether it is located on a shared bus or a bus local to a given system. Because data in the Prestoserve buffer cache of one member is not accessible to other member systems, TruCluster Server cannot provide correct failover when Prestoserve is being used.
Table
Table 4–1: Planning Your Configuration
To increase: | You can: |
Application performance | Increase the number of member systems. |
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I/O performance | Increase the number of shared buses. |
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Member system availability | Increase the number of member systems. |
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Cluster interconnect availability | Use redundant cluster interconnects. |
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TruCluster Server System Configuration Using UltraSCSI Hardware