What will RAID 6 (7+2) change into after dynamic reconstruction of OceanStor Dorado if one SSD failed in a 9-SSD storage pool?
AnswerA
ExplanationHuawei OceanStor Dorado utilizes RAID 2.0+ block virtualization technology, which supports Dynamic RAID Reconstruction. In a traditional RAID environment, if a disk fails, the RAID group continues to operate in a 'degraded' mode until the disk is replaced. However, in Dorado's RAID 2.0+, the system uses a distributed spare space policy where spare capacity is spread across all disks in the pool.
When one SSD fails in a storage pool originally configured with RAID 6 (7 data chunks + 2 parity chunks), the system identifies that it no longer has enough physical disks to maintain a 7+2 stripe width. To maintain the same level of protection (dual parity) while utilizing the remaining 8 disks, the system dynamically adjusts the RAID policy for new writes and reconstructed data to RAID 6 (6+2). This ensures that the data remains protected by two parity chunks even with a reduced disk count. This 'shrinkage' of the stripe width allows the system to remain in a 'healthy' protected state rather than staying in 'degraded' mode indefinitely.