Dell MD3600f, MD3620F Enclosure Loss Protection

Configuration: Disk Groups and Virtual Disks 123

You can use a hot spare physical disk for additional data protection from

physical disk failures that occur in a RAID level 1, or RAID level 5 disk group.

If the hot spare physical disk is available when a physical disk fails, the RAID

controller module uses redundancy data to reconstruct the data from the

failed physical disk to the hot spare physical disk. When you have physically

replaced the failed physical disk, a copyback operation occurs from the hot

spare physical disk to the replaced physical disk.

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 ensure 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.

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