Logical Drive

A logical drive is a partition in a physical array of disks that is made up of contiguous data segments on the physical disks. A logical drive can consist of:

an entire physical array

more than one entire physical array

a part of an array

parts of more than one array, or

a combination of any two of the above conditions

Logical Drive States

 

State

Description

 

 

Optimal

The drive operating condition is good. All configured drives are

 

 

 

online

 

Degraded

The drive operating condition is not optimal. One of the configured

 

 

 

drives has failed or is offline.

 

 

Failed

The drive has failed.

 

 

Offline

The drive is not available to MegaRAID Express 500.

 

 

 

 

 

SCSI Drive States

A SCSI disk drive can be in one of these states:

State

Description

 

 

Online

The drive is functioning normally and is a part of a configured

 

 

(ONLIN)

logical drive.

 

 

Ready

The drive is functioning normally but is not part of a configured

 

 

(READY)

logical drive and is not designated as a hot spare.

 

 

Hot Spare

The drive is powered up and ready for use as a spare in case an

 

 

(HOTSP)

online drive fails.

 

 

Fail

A fault has occurred in the drive placing it out of service.

 

 

(FAIL)

 

 

 

Rebuild

The drive is being rebuilt with data from a failed drive.

 

 

(REB)

 

 

 

 

 

 

Chapter 2 Introduction to RAID

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