Policy

Describe

Primary-Secondary

The system will decide which path to use according to the priorities of all the configured paths among which one path is the primary path and the others are secondary paths. When the configured paths have different priorities, the path with the highest priority is the primary path and is preferred for use. If it fails, a secondary path will be used. When the primary path recovers, it is used again only if its priority is still the highest.

Preferred Path

Among all the configured paths, only one path is the preferred path and is used when it is available. When the preferred path fails, one of the other paths is used. When the preferred path recovers, it is used again.

Load Balance-Round Robin

After transferring a specified number of I/O requests on a current path, the system selects another path for use.

Load Balance-Response Time

Among all available paths, the path with the shortest processing time is used. Processing time = Outstanding I/O requests/Relative throughput

Load Balance-Least Connections

The system records the number of I/O requests being processed by a current path using the least number of connections algorithm. When there is a new I/O, the system selects an optimal path that has the least number of outstanding I/O requests.

Group by Priority

Paths are grouped by priority. The primary-secondary path policy is applied to paths in different groups, and a load balance policy is applied to all paths in a group.

Group by Serial Number

Paths are grouped by serial number. The primary-secondary path policy is applied to paths in different groups, and a load balance policy is applied to all paths in a group.

Group by Name

Paths are grouped by name. The primary-secondary path policy is applied to paths in different groups, and a load balance policy is applied to all paths in a group.