Hello all,
This post is about fully interconnected disk enclosures in dorado V6. The storage system supports three types of disk enclosures, which are SAS, smart SAS, and smart NVMe disk enclosures. Currently, they cannot be used together on one storage system.
Smart SAS and smart NVMe disk enclosures use the same networking mode. In this networking, a controller enclosure uses the shared 2-port 100 Gbit/s RDMA interface modules to connect to a disk enclosure. Each interface module connects to the four controllers in the controller enclosure through PCIe 3.0 x16. In this way, each disk enclosure can be simultaneously accessed by all four controllers, achieving full interconnection between the disk enclosure and the four controllers.
A smart disk enclosure has two groups of uplink ports and can connect to two controller enclosures at the same time. This allows the two controller enclosures (eight controllers) to simultaneously access a disk enclosure, implementing full interconnection between the disk enclosure and eight controllers.
Figure 1 Full interconnection between disk enclosures and eight controllers
When full interconnection between disk enclosures and eight controllers is implemented and the HyperMetro-Inner feature (which creates three cache copies and performs continuous mirroring) is used, the system can tolerate failure of 7 out of 8 controllers.
When SAS disk enclosures are used, they connect to controller enclosures using SAS shared interface modules. Each SAS shared interface module has a built-in SAS switch with 32 protocol channels, which provides eight 12 Gbit/s SAS ports (each port provides 4x12 Gbit/s rate). Four of the ports are connected to four controllers and can be accessed simultaneously by the SAS controllers on the four controllers. The other four ports are connected to SAS disk enclosures using external cables. In this way, the disk enclosures are fully interconnected with all four controllers.
On OceanStor Dorado 3000, 5000, and 6000 V6, a disk enclosure can connect to only one controller enclosure and be accessed only by the controllers in that controller enclosure.
Thank you.
