Method, system, program, and data structures for restricting host access to a storage space

A method for restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, comprising:

• for each cluster group, assigning at least one logical device and at least one host to the cluster group, wherein hosts that are not in the cluster group cannot access the logical devices that are assigned to the cluster group;
• for each cluster group, assigning a logical number to each logical device in the cluster group such that no host member of that cluster group uses the assigned logical number to access another logical device, wherein hosts in the cluster group use the logical number to access the logical device to which the logical number is assigned in the cluster group;
• providing a host list indicating all available hosts, wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group, and wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• receiving a request, including as parameters one input logical device and input cluster group, to add the input logical device to the input cluster group;
• determining whether the input logical device is not assigned one logical number;
• if the input logical device is not assigned one logical number, further performing:
• (i) determining one logical number that is not used by any host assigned to the input cluster group to access one logical device by determining a lowest logical number that is not used by any host assigned to the input cluster group to access one logical device;
• (ii) assigning the determined logical number to the input logical device;
• and
• (iii) updating the host map for each host that is assigned to the input cluster group to indicate that the determined logical number is assigned to the input logical device, wherein after the host maps are updated, each host in the input cluster group can use the determined logical number to access the input logical device.

A method for restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, comprising:

• for each cluster group, assigning at least one logical device and at least one host to the cluster group, wherein hosts that are not in the cluster group cannot access the logical devices that are assigned to the cluster group;
• for each cluster group, assigning a logical number to each logical device in the cluster group such that no host member of that cluster group uses the assigned logical number to access another logical device, wherein hosts in the cluster group use the logical number to access the logical device to which the logical number is assigned in the cluster group;
• providing a host list indicating all available hosts, wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group, wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• receiving a request including as a parameter one input logical device to make accessible to all hosts in the host list;
• determining one cluster group including the input logical device;
• determining the logical number for the input logical device;
• determining whether any host that is not in the determined cluster group including the input logical device uses the determined logical number for the input logical device to access one logical device other than the input logical device;
• and
• updating the host map for each host in the host list to indicate that the determined logical number is assigned to the input logical device if no other host that is not in the determined cluster group uses the determined logical number, wherein after updating the host map for each host in the host list, all the hosts in the host list can use the determined logical number to access the input logical device.

A system for restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, comprising:

• means for assigning at least one logical device and at least one host to at least one cluster group, wherein hosts that are not assigned to one cluster group cannot access the logical devices that are assigned to the cluster group, and wherein multiple hosts are capable of being assigned to one cluster group;
• means for assigning a logical number to at least one logical device in the at least one cluster group such that the at least one host assigned to one cluster group does not use the assigned logical number to access another logical device, wherein the at least one host assigned to one cluster group uses the logical number to access the logical device to which the logical number is assigned in the cluster group, wherein a host list indicates all available hosts and wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group and wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• means for receiving a request, including as parameters one input logical device and input cluster group, to add the input logical device to the input cluster group;
• means for determining whether the input logical device is accessible to all hosts;
• and
• means for updating the host map for each host in one host list that is not assigned to the input cluster group to indicate that the input logical device is not accessible if the input logical device is accessible to all hosts.

A system for restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, and wherein each logical device has a logical device number, comprising:

• means for assigning at least one logical device and at least one host to at least one cluster group, wherein hosts that are not assigned to one cluster group cannot access the logical devices that are assigned to the cluster group;
• means for assigning a logical number to at least one logical device in the at least one cluster group such that the at least one host assigned to one cluster group does not use the assigned logical number to access another logical device, wherein the at least one host in one cluster group uses the assigned logical number to access the logical device to which the logical number is assigned in the cluster group;
• means for providing a host list indicates all available hosts, wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group, wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• means for receiving a request, including as parameters one input logical device and input cluster group, to add the input logical device to the input cluster group;
• means for determining whether the input logical device is not assigned one logical number;
• and
• means for performing if the input logical device is not assigned one logical number:
• (i) determining one logical number that is not used by any host assigned to the input cluster group to access one logical device by determining a lowest logical number that is not used by any host assigned to the input cluster group to access one logical device;
• (ii) assigning the determined logical number to the input logical device;
• and
• (iii) updating the host map for each host that is assigned to the input cluster group to indicate that the determined logical number is assigned to the input logical device, wherein after the host maps are updated, each host in the input cluster group can use the determined logical number to access the input logical device.

A system for restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, and wherein each logical device has a logical device number, comprising:

• means for assigning at least one logical device and at least one host to at least one cluster group, wherein hosts that are not assigned to one cluster group cannot access the logical devices that are assigned to the cluster group;
• means for assigning a logical number to at least one logical device in the at least one cluster group such that the at least one host assigned to one cluster group does not use the assigned logical number to access another logical device, wherein the at least one host in one cluster group uses the assigned logical number to access the logical device to which the logical number is assigned in the cluster group;
• means for providing a host list indicating all available hosts, wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group, wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• means for receiving a request including as a parameter one input logical device to make accessible to all hosts in the host list;
• means for determining one cluster group including the input logical device;
• means for determining the logical number for the input logical device;
• means for determining whether any host that is not in the determined cluster group including the input logical device uses the determined logical number for the input logical device to access another logical device;
• and
• means for updating the host map for each host in the host list to indicate that the determined logical number is assigned to the input logical device if no other host that is not in the determined cluster group uses the determined logical number, wherein after updating the host maps all the hosts in the host list can use the determined logical number to access the input logical device.

An article of manufacture for use in restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, the article of manufacture capable of causing a server controlling access to the physical storage space in communication with the hosts to perform:

• for each cluster group, assigning at least one logical device and at least one host to the cluster group, wherein hosts that are not assigned to the cluster group cannot access the at least one logical device assigned to the cluster group;
• for each cluster group, assigning a logical number to each logical device in the cluster group such that the at last one host assigned to the cluster group does not use the assigned logical number to access a logical device other than the logical device assigned to the logical number, wherein the at least one host assigned to the cluster group uses the logical number to access the logical device to which the logical number is assigned in the cluster group, wherein a host list indicates all available hosts and wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group, and wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• receiving a request, including as parameters one input logical device and input cluster group, to add the input logical device to the input cluster group;
• determining whether the input logical device is accessible to all hosts;
• and
• updating the host map for each host that is not assigned to the input cluster group to indicate that the input logical device is not accessible if the input logical device is accessible to all hosts.

An article of manufacture for use in restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, the article of manufacture capable of causing a server controlling access to the physical storage space in communication with the hosts to perform:

• for each cluster group, assigning at least one logical device and at least one host to the cluster group, wherein hosts that are not assigned to the cluster group cannot access the at least one logical device assigned to the cluster group, and wherein multiple hosts are capable of being assigned to the cluster group;
• for each cluster group, assigning a logical number to each logical device in the cluster group such that the at last one host assigned to the cluster group does not use the assigned logical number to access a logical device other than the logical device assigned to the logical number, and wherein the at least one host assigned to the cluster group uses the logical number to access the logical device to which the logical number is assigned in the cluster group, wherein a host list indicates all available hosts and wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group, and wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• receiving a request, including as parameters one input logical device and input cluster group, to add the input logical device to the input cluster group;
• determining whether the input logical device is not assigned one logical number;
• if the input logical device is not assigned one logical number, further performing:
• (i) determining a lowest logical number that is not used by any host assigned to the input cluster group to access one logical device,
• (ii) assigning the determined logical number to the input logical device;
• and
• (iii) updating the host map for each host in the host list that is assigned to the input cluster group to indicate that the determined logical number is assigned to the input logical device, wherein after the host map for each host in the host list is updated, each host in the input cluster group can use the determined logical number to access the input logical device.

An article of manufacture for use in restricting host access to at least one logical device, wherein each logical device comprises a section of physical storage space that is non-overlapping with the physical storage space associated with other logical devices, the article of manufacture capable of causing a server controlling access to the physical storage space in communication with the hosts to perform:

• for each cluster group, assigning at least one logical device and at least one host to the cluster group, wherein hosts that are not assigned to the cluster group cannot access the at least one logical device assigned to the cluster group;
• for each cluster group, assigning a logical number to each logical device in the cluster group such that the at last one host assigned to the cluster group does not use the assigned logical number to access a logical device other than the logical device assigned to the logical number, and wherein the at least one host assigned to the cluster group uses the logical number to access the logical device to which the logical number is assigned in the cluster group, wherein for each host in the host list there is a host map indicating each logical number accessible to the host;
• receiving a request including as a parameter one input logical device to make accessible to all hosts in the host list;
• determining one cluster group including the input logical device;
• determining the logical number for the input logical device;
• determining whether any host that is not in the determined cluster group including the input logical device uses the determined logical number for the input logical device to access another logical device;
• and
• updating the host map for each host in the host list to indicate that the determined logical number is assigned to the input logical device if no other host that is not in the determined cluster group uses the determined logical number, wherein after updating the host maps all the hosts in the host list can use the determined logical number to access the input logical device.

A computer-readable data transmission medium containing at least one data structure for restricting host access to at least one logical device, comprising:

• information identifying a logical device and a section of physical storage space for the logical device such that the physical storage space is non-overlapping with physical storage space associated with other logical devices;
• information identifying at least one logical device and at least one host assigned to at least one cluster group, wherein, for each cluster group, hosts that are not assigned to the cluster group cannot access the at least one logical device assigned to the cluster group;
• information, for each cluster group, identifying a logical number assigned to the at least one logical device assigned to the cluster group such that the at least one host assigned to the cluster group does not use the assigned logical number to access another logical device, wherein the at least one host assigned to the cluster group uses the assigned logical number to access the logical device to which the logical number is assigned;
• information identifying a host list indicating all available hosts, wherein all hosts in the host list can access a logical device assigned one logical number and not assigned to a cluster group;
• and
• information identifying for each host in the host list a host map indicating each logical number accessible to the host, wherein when one input logical device is added to one input cluster group, the host map for each host that is not assigned to the input cluster group is updated to indicate that the input logical device is not accessible if the input logical device is accessible to all hosts.