Patent ID: 8918557

Claim:
A SAS expander hub apparatus comprising: a processor; a memory connected to the processor; a plurality of PHYs connected to the processor, at least one of the plurality of PHYs configured to connect to a first SAS expander, at least one of the plurality of PHYs configured to connect to a second SAS expander, at least one of the plurality of PHYs configured to connect to a third SAS expander, and at least one of the plurality of PHYs configured to connect to a second SAS expander hub; and computer executable program code, wherein the computer executable program code is configured to: query every device connected to the SAS expander hub to determine the identity of every data storage device directly connected to the SAS expander hub; query every device connected to the SAS expander hub to determine the identity of every data storage device accessible to the SAS expander hub via the first SAS expander, the second SAS expander, the third SAS expander and the second SAS expander hub; compile a data structure associating PHYs in the SAS expander hub with data storage devices accessible via such PHYs; receive an Input/Output (IO) request from the second SAS expander hub; and relay the IO request to at least one of the first SAS expander, the second SAS expander and the third SAS expander; wherein: the first SAS expander is connected to the second SAS expander and the third SAS expander; and the second SAS expander is connected to the third SAS expander.