Chapter 6Protecting Your DataIn addition to the redundancy protection provided to your storage pools by RAID,you can protect your data by assigning hot spares (disk drives that automaticallyreplace failed disk drives) to your storage pools, taking application-consistentsnapshots of it (“pictures” of your data at a particular point in time) for backuppurposes, and mirroring your data (creating an exact copy that is continuouslysynchronized with the original).This chapter explains how to use Adaptec Storage Manager to work with hotspares, snapshots, and mirrored volumes.Protecting Your Data with Hot SparesA hot spare is a disk drive that automatically replaces any failed drive in a pool, andcan 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 anypool in the iSCSI Storage Appliance (except RAID 0 logical devices). You can createa hot spare either before or after you build your pools; you can also create a hotspare 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 thelogical 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 itmight replace.• Adaptec recommends that you not designate a SAS hot spare for a poolcomprising SATA disk drives, or a SATA hot spare for a pool comprising SASdisk drives.
