IBM SAS RAID 5, Manual

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Chapter 5. Dual storage IOA configurations
You can increase availability using a dual storage I/O adapter (IOA) configuration to connect multiple
controllers to a common set of disk expansion drawers and the included disks and disk arrays.
Note: Not all controllers support all configurations. See the PCI-X SAS RAID cards or the PCIe SAS
RAID card comparison tables to look for controllers that have dual storage IOA configurations.
Related concepts
“PCI-X SAS RAID card comparison” on page 3
Use the table in this topic to compare the features of PCI-X SAS RAID cards for IBM i. There are also
images of adapters for you to view.
“PCIe SAS RAID card comparison” on page 6
Use the table in this topic to compare the features of a PCI Express (PCIe) SAS RAID cards for IBM i.
There are also images of adapters for you to view.
Possible disk storage IOA configurations
This topic shows a table illustrating what is needed to have dual storage IOA configurations with RAID
or system mirroring and images of dual storage IOA configurations.
Table 5. Disk protection with dual storage . This table describes what is needed to have dual storage with different
kinds of disk protection.
Multi-initiator configuration Dual storage IOA
RAID
v
Two controllers
v
Both controllers must have the same write cache
capability and write cache sizes
v
Both controllers must support dual storage IOA
configuration
v Controllers are in the same system or partition
System mirroring
v
Four controllers (two pairs of controllers)
v
Each pair of controllers must have the same write
cache capability and write cache sizes
v
Each pair of controllers must support dual storage
IOA configuration
v
Controllers are in the same system or partition
The following figure illustrates an example of a Dual storage IOA configuration with RAID.
© Copyright IBM Corp. 2009
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