Guarding against disk failures

Protection methods to guard against data loss due to disk media failure.

There are various ways to guard against the loss of data due to disk media failures. For example, the use of a RAID controller, which masks disk failures with parity disks, or a twin-tailed disk, could prevent the need for using these recovery steps.

GPFS offers a method of protection that is called replication, which overcomes disk failure at the expense of extra disk space. GPFS allows replication of data and metadata. This means that up to three instances of data, metadata, or both can be automatically created and maintained for any file in a GPFS file system. If one instance becomes unavailable due to disk failure, another instance is used instead. You can set different replication specifications for each file, or apply default settings that are specified at file system creation. Refer to the File system replication parameters topic in the IBM Storage Scale: Concepts, Planning, and Installation Guide.