Mirrored protection concepts
Mirrored protection is a software availability function that protects data from being lost because of failure or because of damage to a disk-related component. Data is protected because the system keeps two copies of data on two separate disk units.
When a disk-related component fails, the system may continue to operate without interruption by using the mirrored copy of the data until the failed component is repaired.
When you start mirrored protection or add disk units to a disk pool that has mirrored protection, the system creates mirrored pairs using disk units that have similar capacities. The overall goal is to protect as many disk-related components as possible. To provide maximum hardware redundancy and protection, the system attempts to pair disk units that are attached to separate I/O buses, IOAs, IOPs, buses, and expansion units.
If a disk failure occurs, mirrored protection is intended to prevent data from being lost. Mirrored protection is a software function that uses duplicates of disk-related hardware components to keep your system available if one of the components fails. It can be used on any model of i5/OS® systems and is a part of the Licensed Internal Code.
Remote mirroring support allows you to have one mirrored disk unit within a mirrored pair at the local site, and the second mirrored disk unit at a remote site. For some systems, standard disk unit mirroring will remain the best choice; for others, remote disk unit mirroring provides important additional capabilities. You must evaluate the uses and needs of your system, consider the advantages and disadvantages of each type of mirroring support, and decide which is best for you.
- How mirrored protection works
Because mirrored protection is configured by disk pool, you can mirror one, some, or all disk pools on the system.- Mirrored protection and performance
When mirrored protection is started, most systems show little difference in performance. There are some cases where mirrored protection can improve performance.- Mirrored protection benefits
Even if your system is not a large one, mirrored protection can provide valuable protection.- Mirrored protection costs and limitations
There are costs and limitations when using mirrored protection.- Concurrent maintenance
Concurrent maintenance is the process of repairing or replacing a failed disk-related hardware component while the system is being used for normal operations.- Advantages of remote disk unit mirroring
There are two advantages of remote mirroring.- Disadvantages of remote load source disk unit mirroring for primary partitions
There are two disadvantages of remote load source disk unit mirroring for primary partitions.
Parent topic:
Mirrored protectionRelated concepts
Benefits of geographic mirroring