Dell MD3220, MD3200 owner manual Enclosure Loss Protection, 117

If there are secure disk groups and security capable disk groups in the storage array, the hot spare physical disk must match the security capability of the disk group. For example, a non-security capable physical disk cannot be used as a hot spare for a secure disk group.

NOTE: For a security capable disk group, security capable hot spare physical disks are preferred. If security capable physical disks are not available, non-security capable physical disks may be used as hot spare physical disks. To ensure that the disk group is retained as security capable, the non-security capable hot spare physical disk must be replaced with a security capable physical disk.

If you select a security capable physical disk as hot spare for a non-secure disk group, a dialog box is displayed indicating that a security capable physical disk is being used as a hot spare for a non-secure disk group.

The availability of enclosure loss protection for a disk group depends on the location of the physical disks that comprise the disk group. The enclosure loss protection may be lost because of a failed physical disk and location of the hot spare physical disk. To make sure that enclosure loss protection is not affected, you must replace a failed physical disk to initiate the copyback process.

The virtual disk remains online and accessible while you are replacing the failed physical disk, because the hot spare physical disk is automatically substituted for the failed physical disk.

Enclosure Loss Protection

Enclosure loss protection is an attribute of a disk group. Enclosure loss protection guarantees accessibility to the data on the virtual disks in a disk group if a total loss of communication occurs with a single expansion enclosure. An example of total loss of communication may be loss of power to the expansion enclosure or failure of both RAID controller modules.

CAUTION: Enclosure loss protection is not guaranteed if a physical disk has already failed in the disk group. In this situation, losing access to an expansion enclosure and consequently another physical disk in the disk group causes a double physical disk failure and loss of data.

Enclosure loss protection is achieved when you create a disk group where all of the physical disks that comprise the disk group are located in different expansion enclosures. This distinction depends on the RAID level. If you choose to create a disk group by using the Automatic method, the software

Configuration: Disk Groups and Virtual Disks

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