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Chapter 2: Storage System Configurations
Figure 2-2
Split-Bus Configuration Example
Caution:
This configuration does not afford failover capability.
If one SP fails or if the SCSI-2 connection from one host is broken, that host
does not have access to the CHALLENGE RAID storage system until the SP
is replaced or the SCSI-2 connection is repaired. The host using the
remaining SCSI-2 connection and remaining operational SP still has full
access to its own data.
The storage-control processor that binds a disk module is the default owner
of the disk module. The route through the SP that owns a disk module is the
primary route to the disk module. The route through the other SP is the
secondary route to the disk module.
In a dual-interface system, either CHALLENGE server can use any of the
disk modules in the storage system, but only one CHALLENGE server at a
time can use a disk module.
Disk modules
owned by SP B (LUN 1)
Disk modules
owned by SP A
(LUN 0)
CHALLENGE 1
CHALLENGE 2
CHALLENGE RAID
SCSI-2 bus
SCSI-2
interface
SP A
SP B
SCSI-2
interface
SCSI-2 bus
