Observe the following guidelines and restrictions when using Fibre Channel for Universal Replicator remote paths:
- When you use 32-Gbps Fibre Channel as a remote path, if you specify Auto for Port Speed, specify 10 seconds or more for Blocked Path Monitoring. If you want to specify 9 seconds or less, do not set Auto for Port Speed.
- If the time specified for Blocked Path Monitoring is not long enough, the network speed slow down or the period for speed negotiation might be exceeded. As a result, paths might be blocked.
- When multiple remote paths share a port, set the same value of blocked path SIM monitoring time for all remote paths.
- When you change the topology (Fabric, FC-AL, point-to-point) of the port being used by a remote path, the new topology might not match that of the remote storage system, resulting in remote path blockage. To prevent this problem, delete the remote path and then change the topology.
- Use the CCI raidcom modify port command to configure a port (port speed, topology). To set Blocked Path Monitoring, use the -path_blocked_watch option of the raidcom modify remote_replica_opt command.Use the CCI raidcom modify port command to configure a port (port speed, topology). To set Blocked Path Monitoring, use the -path_blocked_watch option of the raidcom modify remote_replica_opt command.
- When using 64-Gbps Fibre Channel as a remote path and setting the port speed, be aware of the impact the path blockage monitoring time has on remote copy functionality in the event of a transient failure on all the paths, as shown in the following table. See the caution on setting the data transfer speed for the Fibre Channel port in storage systems in the Provisioning Guide.
|
64-Gbps Fibre Channel port speed settings |
Path blockage monitoring time |
Impact on remote copy functionality in the event of a transient all-path failure |
|---|---|---|
|
Less than 35 seconds (not recommended) |
Remote copy pair might suspend |
|
35 seconds or more (recommended) |
Path recovers within the path blockage monitoring time and remote copy pair remains PAIR |
|
|
Auto |
- (not recommended) |
Remote copy pair might suspend |
When using 64-Gbps Fibre Channel as a remote path, ensure that the transfer speed on the Fibre switch, extender, and other storage system are all set at a fixed 64 Gbps. If a Fiber switch or extender cannot be set to 64 Gbps on the other storage system, set the port speed on the local storage system to "32G fixed " or "16G fixed".
If you use Fibre Channel 64 Gbps for the remote path, the recovery time from intermittent failures is longer than 32 Gbps. If response performance during intermittent failures is important, do not use Fibre Channel 64 Gbps.
You can use only iSCSI to connect remotely to VSP One SDS Block. You cannot use Fibre Channel.