HP MSR Encryption Accelerators - Manual (Page 54)

Monitoring IO Accelerator health 54
About flashback protection technology
Like many other flash devices, NAND flash eventually fails with use. Those failures can be either permanent
or temporary. Flashback Protection redundancy is designed to address those IO Accelerator chips that
experience permanent failures, and provides additional protection above and beyond ECC for soft failures.
Flashback technology provides a real-time RAID-like redundancy at the chip-level, without sacrificing user
capacity or performance for fault tolerance. In general, solutions that use physical RAID schemes for
redundancy/protection, must either sacrifice capacity (RAID 1), or performance (RAID 5).
Flashback Protection technology, with self-healing properties, ensures higher performance, minimal failure,
and longer endurance than all other flash solutions.
Software RAID and health monitoring
Software RAID stacks are typically designed to detect and mitigate the failure modes of traditional storage
media. The IO Accelerator attempts to fail as gracefully as possible, and its new failure mechanisms are
compatible with existing software RAID stacks. A drive in write-reduced mode participating in a write-heavy
workload is evicted from a RAID group for failure to receive data at a sufficient rate. A drive in read-only
mode is evicted when write I/Os are returned from the device as failed. Catastrophic failures are detected
and handled just as though they were on traditional storage devices.