What Does Memory Mirroring Mean?
Memory mirroring is a technique used to separate memory into two separate channels, usually on a memory device, like a server. In memory mirroring, one channel is copied to another to create redundancy. This method makes input/output (I/O) registers and memory appear with more than one address range because the same physical byte is accessible at more than one address. Using memory mirroring, higher memory reliability and a higher level of memory consolidation are possible.
Techopedia Explains Memory Mirroring
The advantages of memory mirroring include the following:
- In the event of failures, like Dual In-line Memory Module (DIMM) failure, the overall system remains unaffected and operational, allowing processes to continue without unscheduled downtime. This is because the memory controller shifts to the other channel without any disruption, and synchronization between channels is established after the issues are resolved.
- With regard to memory processors, memory mirroring facilitates the attainment of the highest possible consistency between memories.
- It is independent of the operating system (OS) used, as it is built into the memory controller. It runs just as easily in Linux and Windows.
- It may be coupled with memory sparing for integrating and installing other hot spare memory modules, as needed.
- It provides full protection for single bit and multiple bit errors.
Memory mirroring's key disadvantage is the higher memory cost required to create this redundancy.