Method, apparatus, and program for improving data mirroring performance in a SCSI topology
US7085903B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 2003 |
| Grant date | Aug 1, 2006 |
| Priority date | — |
| Expiry date | Mar 21, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2087
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A silent mirroring protocol is provided, which eliminates the arbitration/selection times associated with all nexuses after the first nexus. During the initial SCSI bus negotiation, the initiator determines the transfer mode capability of all targets. The initiator establishes a group identification. Participants of the group recognize the group and look for an individual identification within the group. The initiator performs arbitration/selection with attention to the leader of the group. The initiator uses a message out phase with a vendor command to select a participant for a data block transfer. Each participant snoops the bus and recognizes when it is the target. If the initiator has more data to mirror, the process is repeated. When the last data block is transferred, the initiator sends a message out to the last participant, which is interpreted by the target leader as a command to release the bus. Each participant reselects the nexus initiator and returns a status.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.