Adaptec 5325302053 User Guide - Page 67

Chapter 6 Protecting Your Data In addition to the redundancy protection provided to your storage pools by RAID, you can protect your data by assigning hot spares (disk drives that automatically replace failed disk drives) to your storage pools, taking application-consistent snapshots of it ("pictures" of your data at a particular point in time) for backup purposes, and mirroring your data (creating an exact copy that is continuously synchronized with the original). This chapter explains how to use Adaptec Storage Manager to work with hot spares, snapshots, and mirrored volumes. Protecting Your Data with Hot Spares A hot spare is a disk drive that automatically replaces any failed drive in a pool, and can subsequently be used to rebuild that pool. (For more information, see "Recovering from a Disk Drive Failure" on page 150.) Hot spares assigned to iSCSI Storage pools are global hot spares-they protect any pool in the iSCSI Storage Appliance (except RAID 0 logical devices). You can create a hot spare either before or after you build your pools; you can also create a hot spare while you're creating a pool. To create a hot spare, see page 62. An assigned hot spare are dedicated hot spares-they are used only to rebuild the logical devices to which they are assigned. Hot Spare Limitations • You can't create a hot spare for RAID 0 pools. • You can't create a hot spare from a disk drive that is already part of a pool. • You should select a disk drive that is at least as big as the largest disk drive it might replace. • Adaptec recommends that you not designate a SAS hot spare for a pool comprising SATA disk drives, or a SATA hot spare for a pool comprising SAS disk drives.