HP StorageWorks Scalable File Share System Installation and Upgrade Guide Version 2.2

Object Storage Server storage topology 1–13
1.4.2.1 Dual-connected SFS20 configuration
A dual-connected SFS20 configuration consists of a pair of SFS20 arrays, each of which is connected to
two servers. In normal operation, one server accesses one of the SFS20 arrays, while the other server
accesses the second array. If one of the servers in the server pair fails, the other server accesses both SFS20
arrays.
Figure 1-9 shows a dual-connected SFS20 configuration.
Figure 1-9 Dual-connected SFS20 configuration
A dual-connected SFS20 configuration consists of the following components:
• Two Object Storage Servers
• Two SFS20 arrays (see Table 1-2)
• Four SCSI cables
• At least one Smart Array 6404 HBA per server
Variations of this configuration can have up to three more pairs of SFS20 arrays per server pair, using up
to two Smart Array 6404 HBAs on each server. This is the maximum configuration.
A dual-connected configuration can tolerate the following problems:
• Loss of a SCSI connection to one of the two servers in a pair—the other server in the pair can access
the data.
• Loss of an Object Storage Server due to a hardware or software fault—the other server in the pair
can continue to operate.
• Loss of a disk within the SFS20 RAID array—the hardware RAID functionality provides redundancy
and sparing to rebuild the RAID disk.
• Loss of one power supply to an SFS20 array—the array has redundant power supplies and a battery-
backed cache.
Server 1 Server 2
6404
SFS20 2
A1 A2 B1 B2
6404
A1 A2 B1 B2
SFS20 1
Failover
Failover
Normal
Access
Normal
Access