of a virtual disk. The target disk needs to be a hot spare that qualifies as a rebuild disk. The physical disk with theSMART error is marked as failed only after the successful completion of the Replace Member. This avoids putting thearray in degraded status.If an automatic Replace Member occurs using a source disk that was originally a hot spare (that was used in a rebuild),and a new disk added for the Replace Member operation as the target disk, the hot spare reverts to the hot spare stateafter a successful Replace Member operation.NOTE: To enable the automatic Replace Member, use the Dell OpenManage storage management application. Formore information on automatic Replace Member, see the topic Dell OpenManage Storage Management. Forinformation on manual Replace Member, see the topic Replacing An Online Physical Disk.Patrol ReadThe Patrol Read feature is designed as a preventative measure to ensure physical disk health and data integrity. PatrolRead scans for and resolves potential problems on configured physical disks. The Dell OpenManage storagemanagement application can be used to start Patrol Read and change its behavior.The following is an overview of Patrol Read behavior:• Patrol Read runs on all disks on the controller that are configured as part of a virtual disk, including hot spares.• Patrol Read does not run on physical disks that are not part of a virtual disk or are in Ready state.• Patrol Read adjusts the amount of controller resources dedicated to Patrol Read operations based onoutstanding disk I/O. For example, if the system is busy processing I/O operation, then Patrol Read uses fewerresources to allow the I/O to take a higher priority.• Patrol Read does not run on any disks involved in any of the following operations:– Rebuild– Replace Member– Full or Background Initialization– CC– RLM or OCENOTE: By default, Patrol Read automatically runs every seven days on configured SAS and SATA harddrives. Patrol Read is not necessary on SSD and is disabled by default.For more information on Patrol Read, see the Dell OpenManage documentation at dell.com/support/manuals.Redundant Path Support (For PERC H810 Only)The PERC H810 adapter can detect and use redundant paths to disks contained in enclosures. This provides the ability toconnect two SAS cables between a controller and an enclosure for path redundancy. The controller is able to toleratethe failure of a cable or Enclosure Management Module (EMM) by utilizing the remaining path.When redundant paths exist, the controller automatically balances I/O load through both paths to each disk. Loadbalancing increases throughput to virtual disks in storage enclosures and is automatically turned on when redundantpaths are detected. The ability to load balance I/O can be disabled using the Dell OpenManage storage managementapplication.To set up your hardware to support redundant paths, see the topic Setting Up Redundant Path Support On The PERCH810 Adapter.NOTE: This support for redundant paths refers to path-redundancy only and not to controller-redundancy.21