Chapter 4

RAID Protection of Data

About this chapter

This chapter describes how to manage RAID protection on storage system aggregates. Throughout this chapter, the term aggregate refers to an aggregate that contains either FlexVol volumes or traditional volumes.

Data ONTAP uses RAID Level 4 or RAID-DP (double-parity) protection to ensure data integrity within a group of disks even if one or two of those disks fail.

Note
The RAID principles and management operations described in this chapter do not apply to V-Series systems. Data ONTAP uses RAID-0 for V-Series systems since the LUNs that they use are RAID protected by the storage subsystem.

Topics in this chapter

This chapter discusses the following topics:

Understanding RAID groups
Predictive disk failure and Rapid RAID Recovery
Disk failure and RAID reconstruction with a hot spare disk
Disk failure without a hot spare disk
Replacing disks in a RAID group
Setting RAID level and group size
Changing the RAID level for an aggregate
Changing the size of RAID groups
Controlling the speed of RAID operations
Automatic and manual disk scrubs
Minimizing media error disruption of RAID reconstructions
Viewing RAID status