Patent ID: 7171514

Claim:
A method to control access to logical volumes disposed in an information storage and retrieval system using parallel access volumes, comprising the steps of: providing an information storage and retrieval system comprising a plurality of logical volumes; providing a plurality of host computers, wherein each of said plurality of host computers is capable of communicating with said information storage and retrieval system; forming (N) host computer groups, wherein (N) is greater than or equal to 1; assigning each host computer to the a host computer group; forming (N) logical volume groups; assigning one or more of said plurality of logical volumes to a logical volume group; creating a parallel access volume having an alias; persistently associating said parallel access volume with a base logical volume, wherein said base logical volume is assigned to the (i)th logical volume group, wherein (i) is greater than or equal to 1 and less than or equal to (N); permitting each host computer assigned to the (i)th host computer group to access said parallel access volume; receiving a request to assign to a logical volume group the base logical volume associated with a parallel access volume; determining if the base logical volume associated with said parallel access volume differs from the original base logical volume associated with said parallel access volume; operative if the base logical volume associated with said parallel access volume does not differ from the original base logical volume associated with said parallel access volume, assigning the base logical volume associated with said parallel access volume to said logical volume group; operative if the base logical volume associated with said parallel access volume differs from the original base logical volume associated with said parallel access volume: reassigning the alias for said parallel access volume to said original base logical volume; and assigning to said logical volume group said base logical volume associated with said parallel access volume.