Abstract: A method to control access to logical volumes. The method provides a plurality of host computers and an information storage and retrieval system comprising a plurality of logical volumes. The method forms (N) host computer groups, assigns one or more of the host computers to the (i)th host computer group, such that each host computer assigned to (i)th host computer group is not assigned to any other of the (N) host computer groups. The method forms (N) logical volume groups, assigns one or more logical volumes to the (i)th logical volume group, such that each of the logical volumes assigned to the (i)th logical volume group is not assigned to any other of the (N) logical volume groups. The method maintains a database associating the (i)th host computer group with the (i)th logical volume group, and permits a host computer assigned to the (i)th host computer group to access a logical volume assigned to the (i)th logical volume group.

Abstract: A method to control access to logical volumes disposed in an information storage and retrieval system using parallel access volumes. The method provides an information storage and retrieval system comprising a plurality of logical volumes, and a plurality of host computers, where each host computers is capable of communicating with the information storage and retrieval system. The method creates a parallel access volume having an alias, and persistently associates that parallel access volume with an original base logical volume, where the original base logical volume may be assigned to one of (N) logical volume groups. If the original base logical volume is assigned to the (i)th logical volume group, the method permits each host computers assigned to the (i)th host computer group to access the original base logical volume, or the current base logical volume, associated with the parallel access volume.

Abstract: A method to control access to logical volumes disposed in one or more information storage and retrieval systems when using copy service relationships. The method provides a first information storage and retrieval system, a second information storage and retrieval system, and a plurality of host computers capable of communicating with the first information storage and retrieval system. The method forms (N) host computer group, and assigns each of the plurality of host computers to the a host computer group. The method forms (N) logical volume groups, and assigns one or more of the plurality of first logical volumes to a logical volume group. The method receives a request from a host computer assigned to the (i)th host computer group to establish a copy service relationship between a source logical volume and a target logical volume. The method determines if both the source and target logical volumes are assigned to the (i)th logical volume group.