Detection of SCSI devices at illegal locations
First Claim
1. In a computing system having a plurality of computing system interface devices connected to a host computer through a computing system interface bus and one or more controllers on the bus, said plurality of devices being configurable to actual or alias bus addresses depending on whether the device is installed in a correct or illegal slot attached to the bus, a method for detecting computing system interface devices installed in illegal slots, said method comprising the computer implemented steps of:
- first detecting a computing system interface device installed in an illegal slot that configures the device to an alias bus address that conflicts with a controller bus address; and
second detecting a computing system interface device installed in an illegal slot that configures the device to an alias bus address that conflicts with an actual bus address corresponding to the alias bus address.
3 Assignments
0 Petitions
Accused Products
Abstract
In a SCSI subsystem having mixed wide and narrow SCSI devices installed, a method and apparatus is provided for detecting a narrow SCSI device illegally installed at a slot assigned to a wide SCSI device. To detect the narrow SCSI device installed at an illegal location, high ID and low ID SCSI bus address pairs are set as test pairs for the SCSI subsystem. The low ID is the alias of the high ID if a narrow SCSI device is installed at the high ID slot. To detect a conflict with a controller ID, a non-responsive ID bus address corresponding to a slot known to be unused is called. A response to this call indicates a narrow SCSI device is installed at the high ID of the test pair and the narrow SCSI device at the high ID has configured to an alias bus address matching the controller ID. To detect a present conflict between SCSI devices, the low ID bus address in the test pair is called. A conflict in responses indicates a SCSI device is installed at the low ID and a narrow SCSI device is installed at the high ID of the test pair. To detect a future conflict between a narrow SCSI device at a high ID and a SCSI device installed in the future at an unused low ID, both the low ID and the high ID are called. No response to the high ID call in combination with a response to the low ID call indicates a narrow SCSI device is installed at the high ID and the narrow SCSI device would conflict in the future with a SCSI device subsequently installed at the unused low ID.
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Citations
19 Claims
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1. In a computing system having a plurality of computing system interface devices connected to a host computer through a computing system interface bus and one or more controllers on the bus, said plurality of devices being configurable to actual or alias bus addresses depending on whether the device is installed in a correct or illegal slot attached to the bus, a method for detecting computing system interface devices installed in illegal slots, said method comprising the computer implemented steps of:
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first detecting a computing system interface device installed in an illegal slot that configures the device to an alias bus address that conflicts with a controller bus address; and second detecting a computing system interface device installed in an illegal slot that configures the device to an alias bus address that conflicts with an actual bus address corresponding to the alias bus address. - View Dependent Claims (2, 3, 4, 5)
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6. In a computing system having small computing system interface (SCSI) subsystem connecting a plurality of SCSI devices through a SCSI bus to a subsystem controller in the computing system;
- said plurality of SCSI devices being of at least two types, wide and narrow, wide SCSI devices configurable to an actual ID bus address when the wide SCSI device is installed at either a low ID slot or a high ID slot attached to the SCSI bus, narrow SCSI devices configurable to an actual low ID bus addresses when installed in a low ID slot and configurable to an alias low ID bus address when installed in a high ID slot;
a method for detecting narrow SCSI devices installed in high ID slots comprising the steps of;first detecting a narrow SCSI device installed at a high ID and aliasing to a low ID that matches a controller ID bus address for the controller attached to the SCSI bus; second detecting a narrow SCSI device installed at a high ID and aliasing to a low ID address corresponding to a slot where another SCSI device is installed; and third detecting a narrow SCSI device installed at a high ID and aliasing to a low ID address corresponding to an unused slot where another SCSI device may be installed in the future. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15)
- said plurality of SCSI devices being of at least two types, wide and narrow, wide SCSI devices configurable to an actual ID bus address when the wide SCSI device is installed at either a low ID slot or a high ID slot attached to the SCSI bus, narrow SCSI devices configurable to an actual low ID bus addresses when installed in a low ID slot and configurable to an alias low ID bus address when installed in a high ID slot;
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16. In a computing system having small computing system interface (SCSI) subsystem connecting a plurality of SCSI devices through a SCSI bus to a subsystem controller in the computing system;
- said plurality of SCSI devices being of at least two types, wide and narrow, wide SCSI devices configurable to an actual ID bus address when the wide SCSI device is installed at either a low ID slot or a high ID slot attached to the SCSI bus, narrow SCSI devices configurable to an actual low ID bus addresses when installed in a low ID slot and configurable to an alias low ID bus address when installed in a high ID slot;
apparatus in the controller for detecting narrow SCSI devices installed in high ID slots comprising;a set module setting high ID and low ID address pairs as test pairs for the SCSI subsystem, said low ID being the alias of the high ID if a narrow SCSI device is installed at the high ID slot; a first address module calling a non-responsive ID bus address corresponding a slot known to be unused; first test module detecting a response when said first address module calls the non-responsive ID bus address, the response indicating a narrow SCSI device is installed at the high ID of the test pair and the narrow SCSI device has configured to an alias bus address matching the controller ID; a second address module generating a call to the low ID bus address in the test pair; a second test module detecting a conflict in responses when said second address module calls the low ID, the conflict indicating a SCSI device is installed at the low ID and a narrow SCSI device is installed at the high ID of the test pair; a third address module generating a call to the high ID bus address in the test pair; a third test module detecting no response to the call from said third address module and detecting a response to the call from said second address module, this combination of response and no response indicating a narrow SCSI device is installed at the high ID and the narrow SCSI device would conflict in the future with a SCSI device subsequently installed at the unused low ID. - View Dependent Claims (17, 18, 19)
- said plurality of SCSI devices being of at least two types, wide and narrow, wide SCSI devices configurable to an actual ID bus address when the wide SCSI device is installed at either a low ID slot or a high ID slot attached to the SCSI bus, narrow SCSI devices configurable to an actual low ID bus addresses when installed in a low ID slot and configurable to an alias low ID bus address when installed in a high ID slot;
Specification