Planning for I/O connections
Plan to install the appropriate adapters for your FlashSystem control enclosure so that it is compatible with your networking topology and provides the appropriate connection capability.
The control enclosure contains two node canisters. Each node canister has three PCIe interface slots for adapters. Additionally, each node canister has four Onboard Ethernet ports for management, host I/O, and replication.
Important: Both node canisters
in a control enclosure (I/O group) must be configured with the same adapters.
Note: The node canister in the upper slot
(slot 1) of a control enclosure is inverted, so the adapter slots and port numbers are numbered from
right to left. The adapters and ports of the node canister in the lower slot
(slot 2) are numbered left to right.
Table 1 provides
examples of the connection types and the alternative connection methods if alternative connection
methods are available.
| Functionality | Network speeds supported | On-board or Adapter | Host I/O | System to system | Storage virtualization |
|---|---|---|---|---|---|
| Fibre Channel SAN (SCSI) | 32 Gb, 16 Gb | Adapter: 4-port | yes | yes | yes |
| Fibre Channel SAN (FC-NVMe) | 32 Gb, 16 Gb | Adapter: 4-port | yes | no | no |
| Ethernet (iSCSI) | 25 Gb | Adapter: 2-port | yes | yes | yes |
| 10 Gb | On-board: 4-port | yes | yes | no | |
| Ethernet (NVMe/TCP and NVMe/RDMA) | 25 Gb | Adapter: 2-port | yes | yes | no |
Note: 2 port adapter with port speed 25 Gb or
10 Gb depends on transceiver installation. For more information on the adapter, see Cable reference.
Connecting two control enclosures directly with Fibre Channel cables
Two control enclosures can be
directly connected to form a partnership (for Policy-based High Availability, migration or
replication), or to form a clustered HyperSwap system for legacy high availability support. Creating
a clustered system prevents the use of newer features such as storage
partitions and policy-based High Availability.
Note: Remote
copy (including HyperSwap, Metro Mirror, Global Mirror, and volume mobility) is not supported from
software version 8.7.1 onwards. These services are replaced by policy-based high availability and
policy-based
replication.
Note: Clustering between the systems is supported for the systems running 8.7.0 or
earlier software versions.
It is best for reliability, availability, and serviceability for control enclosures to communicate with each other through network switches. However, they can be directly connected with Fibre Channel (FC) cables, if needed.
Each node canister must have at least two paths to each node canister in the other control
enclosure. This means that at least 8 Fibre Channel cables are needed and at least four Fibre
Channel ports on each node canister will be used. Table 2 shows an example
of Fibre Channel connections between the enclosures.
| Control enclosure 1 | Control enclosure 2 | |||
|---|---|---|---|---|
| FC Cable | Node Canister | FC Port | Node Canister | FC Port |
| 1 | 1 | 1 | 1 | 1 |
| 2 | 1 | 2 | 2 | 1 |
| 3 | 1 | 3 | 1 | 2 |
| 4 | 1 | 4 | 2 | 2 |
| 5 | 2 | 1 | 1 | 3 |
| 6 | 2 | 2 | 2 | 3 |
| 7 | 2 | 3 | 1 | 4 |
| 8 | 2 | 4 | 2 | 4 |