Physical disk power management, Using the smart feature – Dell PowerEdge RAID Controller H700 User Manual

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Storage Controller Features

Physical Disk Power Management

The PERC H700 and H800 cards can be configured to spin down certain hard

drives after a set amount of time of inactivity to conserve power. This

power-savings feature is disabled by default and can be enabled in the Dell

OpenManage storage management application.
The power-savings feature can be enabled so that unconfigured disks, hot

spares, or both are spun down. The amount of time to wait to spin down these

disks can also be set. The minimum amount of time to wait that can be set is

30 minutes and the maximum is 1 day. The default is 30 minutes.
Disks that are spun down automatically, spin up when they are needed for

use. When a system is rebooted, all disks spin up.

Using the SMART Feature

The Self-Monitoring Analysis and Reporting Technology (SMART) feature

monitors the internal performance of all motors, heads, and physical disk

electronics to detect predictable physical disk failures. The SMART feature

helps monitor physical disk performance and reliability. SMART-compliant

physical disks have attributes for which data can be monitored to identify

changes in values and determine whether the values are within threshold

limits. Many mechanical and electrical failures display some degradation in

performance before failure.
A SMART failure is also referred to as a predicted failure. There are numerous

factors that relate to predicted physical disk failures, such as a bearing failure,

a broken read/write head, and changes in spin-up rate. In addition, there are

factors related to read/write surface failure, such as seek error rate and

excessive bad sectors. For information on physical disk status, see "Disk

Roaming" on page 26.

NOTE:

For detailed information on SCSI interface specifications, see t10.org

and for detailed information on SATA interface specifications, see t13.org.

PERC7.2_UG.book Page 24 Thursday, March 3, 2011 2:14 PM

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