Users Guide

• Shared device is not supported when the external PCIE slot is occupied by a shared adapter. Using the shared adapter, you can
support shared device by changing the shared storage VA pool.
Fault-Tolerance in Storage Controllers
High Availability (HA) in storage enables availability of multiple integrated components and multiple access points to storage resources. In
case a storage component stops functioning, the server is supported by a second critical component or path to the available data. High
Availability only minimizes downtime by restoring services behind the scenes, in most cases before the non-functionality is visible, but does
not eliminate downtime. Fault Tolerance (FT) makes use of redundant components within a storage system, which are configured to
behave as backup components and are kept in standby mode. Storage Controllers in fault-tolerant mode prevent disruption of storage
services and automatically take over the services of a component that has stopped functioning. Performance remains consistent
throughout this failover process since the redundant components(controllers) are not used during normal operating conditions.
High Availability with fault-tolerance provides the following benefits:
• Provides uptime for all storage applications even when a controller stops functioning.
• Provides access to critical functions of the chassis at all times.
• Enables server to handle situations when controller stops functioning are becomes faulty.
• Makes use of component redundancy
Using the fault-tolerant feature of controllers, you can manage the tasks associated with shared storage that are achieved by having an
active and passive (peer) controller. Active controller is the controller that is active and monitors all the storage-related processes.
Working status of both controllers are communicated between controllers so that when an active controller stops functioning, the passive
controller acting as a peer hot-spare, takes over in a seamless manner.
NOTE: CMC displays fault-tolerant data for Shared PERC 8’s with SR-IOV enabled firmware. If a non-SR-IOV card is
attached to the shared storage slots the card does not power on and an alert is generated.
Viewing Controller Properties Using CMC Web
Interface
To view the controller properties:
1. In the left pane, click Chassis Overview > Controller.
2. On the Controllers page, under the Controllers section, you can see the basic properties of the controller. However, to view the
advanced properties, click the
.
NOTE:
If the Controllers are in fault-tolerant mode, then the following information regarding the fault-tolerant
status and mode is also displayed:
• Fault Tolerant Mode – Shared, Active/Passive
• Fault Tolerant Status – Healthy/Normal, or Lost/Degraded
• Peer Controller - Indicates the name of controller that acts as the peer (stand-by) in case of a fault-tolerant
mode supported by two controllers
NOTE: If the peer controller is disabled, the name is displayed as Disabled PERC (Integrated 2) or Disabled
PERC(SPERC Slot 6) and the Status is displayed as Unknown, which implies that the peer controller is turned off.
For more information about Controllers, see the Online Help.
Viewing Controller Properties Using RACADM
To view controller properties using RACADM, run the command racadm raid get controllers -o
For more information, see the Chassis Management Controller for PowerEdge VRTX RACADM Command Line Reference Guide.
Importing or Clearing Foreign Configuration
A foreign disk must be inserted into the chassis.
To import or clear the foreign configuration:
Managing Chassis Storage
167