Techniques for overriding device reservations

A method for overriding an existing device reservation comprising:

• performing discovery processing by a first data storage system to locate a specified device, said discovery processing including determining whether there is a reservation conflict for said device of a second data storage system;
• if there is a reservation conflict for said device, issuing a command from the first data storage system to the second data storage system during said discovery processing to create an override for said reservation conflict, said override causing processing to be performed at a subsequent point in time so that an existing reservation associated with the reservation conflict is overridden in connection with performing a first process on said first data storage system;
• issuing an inquiry command to the second data storage system to determine a type of said second data storage system;
• determining, in accordance with said type of the second data storage system, whether said second data storage system supports reservation override processing;
• and
• only issuing said command to create an override if said second data storage system supports reservation override processing.

A method for overriding an existing device reservation comprising:

• performing discovery processing by a first data storage system to locate a specified device, said discovery processing including determining whether there is a reservation conflict for said device of a second data storage system;
• if there is a reservation conflict for said device, issuing a command from the first data storage system to the second data storage system during said discovery processing to create an override for said reservation conflict, said override causing processing to be performed at a subsequent point in time so that an existing reservation associated with the reservation conflict is overridden in connection with performing a first process on said first data storage system;
• performing said discovery processing a first time in which no reservation conflicts for said device are determined;
• performing processing for said first process, said processing including performing a data operation for said device;
• determining an error in connection with performing said data operation;
• and
• performing said discovery processing a second time in which a reservation conflict for said device is determined.

A method for overriding an existing device reservation comprising:

• determining, by a first initiator, whether there is a reservation conflict for a device of a remote data storage system;
• if there is a reservation conflict for said device, issuing a command by the first initiator to the remote data storage system to create an override for said reservation conflict, said command being issued by said first initiator on a path from said initiator to said remote data storage system, said override allowing said initiator to proceed with subsequent data operations to said device sent using said path from said initiator to said remote data storage system, wherein override information for overriding an existing reservation of said device is stored in accordance with said command;
• receiving, at the remote data storage system, a subsequent command for said device sent over an associated communication path;
• and
• determining whether to allow said subsequent command, said determining including determining whether said associated communication path is identified in the override information, wherein, the subsequent command is not allowed if the associated communication path is not accordingly identified in the override information.

A computer readable medium comprising code stored thereon for overriding an existing device reservation, the computer readable medium comprising code that:

• determines, by a first initiator, whether there is a reservation conflict for a device of a remote data storage system;
• if there is a reservation conflict for said device, issues a command by the first initiator to the remote data storage system to create an override for said reservation conflict, said command being issued by said first initiator on a path from said initiator to said remote data storage system, said override allowing said initiator to proceed with subsequent data operations to said device sent using said path from said initiator to said remote data storage system, wherein override information for overriding an existing reservation of said device is stored in accordance with said command;
• receives at the remote data storage system, a subsequent command for said device sent over an associated communication path;
• and
• determines whether to allow said subsequent command, said code that determines including code that determines whether said associated communication path is identified in the override information, wherein, the subsequent command is not allowed if the associated communication path is not accordingly identified in the override information.