Single path and multipath configurations for the NVMe Expansion Drawer - 24 devices (NED24)
The NED24 NVMe expansion drawer supports single path and multipath configurations.
The NED24 NVMe expansion drawer provides the ability to attach up to 24 NVMe U.2 drives and supports both single path and multipath configurations. The drawer contains two Enclosure Services Managers (ESMs) that provide connectivity to the NVMe U.2 drives. In a single path configuration, only one ESM is used to communicate with an NVMe U.2 drive. In a multipath configuration, both ESMs are used to communicate with an NVMe U.2 drive.
- Each NVMe U.2 drive that is installed in a NED24 NVMe expansion drawer is accessible by two independent paths.
- A multipath configuration is fault tolerant. In the case of a single path failure, the operating system routes I/O commands through the remaining path transparent to the application.
- A multipath configuration yields increased system performance due to load balancing of I/O operations across multiple paths.
- Two paths allow concurrent maintenance of the ESM, expansion drawer cable, or cable adapter without losing access to any storage in the NED24 NVMe expansion drawer.
All the NVMe U.2 drives that are supported in the NED24 NVMe expansion drawer are multipath capable. However, system firmware level FW1060.10 or later, is required. When using FW1060.10 or later, both drive paths must be assigned to a single logical partition using the HMC's logical partition Physical I/O Adapters page or through the partition’s profile. Each NVMe U.2 drive in the NED24 NVMe expansion drawer has a "-R1" or "-R2" suffix added to the end of its physical location code. The Partner Location Code column can be used to identify the other path to the NVMe U.2 drive in a multipath configuration.