Dell PowerEdge RAID Controller H800 - Manual (Page 64)

64 Installing and Configuring Hardware
Setting up Redundant Path Support on the
PERC H800 Adapter
The PERC H800 adapter can detect and use redundant paths to disks
contained in enclosures. With redundant paths to the same device, if one
path fails, another path can be used to communicate between the controller
and the device. For more information about redundant paths, see "Redundant
Path With Load Balancing Support" on page 35.
To set up a configuration with redundant paths, both ports on a controller
must be cabled to the In ports of a single enclosure.
To add multiple enclosures, both Out ports of the first enclosure must be
cabled to the In ports of the next enclosure.
If the connection between an Out port on the controller and an In port on an
enclosure fails, an alternate path exists through the second Out port on the
controller and the second In port on the enclosure. For more information,
see Figure 4-18 to Figure 4-21.
NOTE: The PERC H800 adapter supports redundant paths when used with
Dell PowerVault MD1200 and Dell PowerVault MD1220 disk storage enclosures.
Perform the following steps to configure the hardware to utilize redundant
paths on the PERC H800 adapter:
1 Set up an enclosure on the PERC H800 adapter.
2 Connect two SAS cables from the Out ports on your PERC H800 adapter
to the In ports of the external enclosure. For more information,
see Figure 4-18.
NOTE: For information on Unified Mode, see the enclosure documentation
that was shipped with the enclosure.
3 To add multiple enclosures, cable both Out ports of the first enclosure to
both In ports of the next enclosure.
After you set up the hardware, the controller detects the redundant paths and
automatically utilizes them to balance the I/O load.
PERC7.2_UG.book Page 64 Thursday, March 3, 2011 2:14 PM