Method and arrangement for generating unique identifiers for logical units of SCSI devices

An arrangement for generating a unique identifier for one of a plurality of logical unit on a small computer system interface (SCSI) device, comprising:

• means for querying one of the plurality of logical units on the SCSI device with a first command requesting first identifier data;
• means for determining whether a unique identifier (UID) for the queried logical unit can be constructed based on any first identifier data received by the client, the UID distinguishing uniquely among the plurality of logical units on the SCSI device,
• the means for querying further querying the logical unit with a second command requesting second identifier data, if the means for determining concludes that the UID cannot be constructed from the first identifier data;
• the means for determining further determining whether the UID for the queried logical unit can be constructed based on the second identifier data, and
• the means for querying further querying the logical unit with a third command requesting third identifier data, if the means for determining concludes that the UID cannot be constructed from the second identifier data;
• means for extracting information from the first identifier data and from the third identifier data;
• and
• means for generating the UID based on the extracted information.

A method for generating a unique identifier for one of a plurality of logical units on a small computer system interface (SCSI) device, comprising the steps of:

• querying one of the plurality of logical units on the SCSI device with a SCSI command requesting a standard inquiry page from the logical unit;
• storing data from the standard inquiry page, the data including at least one or more of vendor identification data, product identification data and product revision level data of the logical unit;
• determining whether there is an applicable specialized method available for generating a unique identifier (UID) for the queried logical unit based on the stored data, the UID distinguishing uniquely among the plurality of logical units on the SCSI device;
• querying the logical unit with another SCSI command requesting a logical unit identification vital product data (VPD) page from the logical unit, if no specialized method is available;
• querying the logical unit with a further SCSI command requesting a unit serial number vital product data (VPD) page from the logical unit, if a logical unit identification VPD page is not received from or supported by the logical unit;
• extracting a product serial number form the unit serial number VPD page;
• and
• generating the UID for the queried logical unit based on only the product serial number and at least one or more of vendor identification data, product identification data and product revision level data of the logical unit.

A computer program product comprising a computer-readable medium having computer program logic stored thereon for enabling a processor of the product to generate a unique identifier for one of a plurality of logical units on a small computer system interface (SCSI) device, the computer program logic causing the processor to perform the steps of:

• querying one of the plurality of logical units on the SCSI device with a first command requesting first identifier data;
• determining whether a unique identifier (UID) for the queried logical unit can be constructed based upon the first identifier data, the UID distinguishing uniquely among the plurality of logical units on the SCSI device;
• querying the logical unit with a second command requesting second identifier data, if the UID cannot be constructed from the first identifier data;
• determining whether the UID for the queried logical unit can be constructed based on the second identifier data;
• querying the logical unit with a third command requesting third identifier data, if the UID cannot be constructed from the second identifier data;
• extracting information from the first identifier data and from the third identifier data;
• and
• generating the UID based on the extracted information.