Peripheral device initiated partial system reconfiguration

Claim 2

A data processing system including one or more host processors connected by one or more channels to one or more peripheral sub-systems including one or more devices or sections capable of external servicing or replacement, wherein the or each sub-system is adapted to accept an external command to the system to reconfigure a device or section designated for service or replacement out of the system or, when serviced or replaced, it or its replacement into the system and to transmit such command to all relevant connected hosts via all relevant independently connected channels and to receive from such hosts and to display externally of the sub-system indications that the commanded reconfiguration in or out has been completed.

Claim 3

A system as claimed in claim 1 wherein each sub-system which supports a plurality of addressable devices includes, in combination: in each of the devices, a command input portion for receiving commands independently of the host system; reconfigure request means in the sub-system, operatively coupled to the input portions for receiving input commands indicating that a given one of the devices is to be maintained in an off-line condition which prevents access to the device by the host system to generate a quiesce request or alternatively is to be restored to addressability to generate a corresponding device quiesce/restore request; communication means to send to the host system the device quiesce/restore request; there being configuration control means in the host system having a configuration table and being operatively coupled to the communication means to receive such device quiesce/restore request and, responsive thereto, to determine whether or not to allow such quiesce/restore request and to effect the appropriate reconfiguration in the host system when allowable and record same in the host system configuration table, removing or restoring addressability to the device; and response means in the configuration control means to generate a write system status command and to supply the same to the communication means indicating host system approval or denial of the requested reconfiguration.

Claim 4

A system as claimed in claim 2, wherein there are a plurality of channel paths extending between one host system and one peripheral sub-system, of which predetermined ones of the channel paths are logically grouped, the communication means including means for sending a request over each of the channel paths which are includable into an access path between the host system and a the device to be quiesced excepting that in the channel paths belonging to a group of channel paths the request is sent over any single one of the channel paths within the respective group of channel paths.

Claim 5

A system as claimed in claim 3, wherein one peripheral sub-system includes a plurality of programmed control units and a larger plurality of peripheral units, the reconfiguration request means including the communication means in each of the control units, which are independently operable to make reconfiguration requests; each of the control units including devices within a access path of the peripheral sub-system which are path devices and each of the peripheral units including at least one device which is a peripheral device with interconnections between the control units and the peripheral units such that each peripheral unit can be accessed by any one of a plurality of path devices in either of the control units; each of the control units having a configuration path for each of the peripheral devices which includes identification of all internal access paths of the sub-system including identification of the path devices and further including a configuration path for each of the path devices which of the peripheral devices are accessible via the respective path device; and the communication means sensing the maps for determining which of the channel paths and channel path groups to send the request over to the host system.

Claim 7

A system as claimed in claim 5, further including, in combination: an operator console connected to the host system for providing communication between and operator and a host system; and the reconfiguration control means in the host system being coupled to the console and for each request received for reconfiguration supplying a message to the console for obtaining approval of the operator for such requested reconfiguration before approving such requested reconfiguration.

Claim 8

A system as claimed in claim 5 or claim 6, wherein the configuration control means is operatively coupled to the stored configuration maps and having analysis means performing the analysis including examining the stored configuration maps to ascertain whether the requested configuration would remove the last access path to any of the devices and approving the reconfiguration only if at least one access path remain for any of the devices in the sub-system.

Claim 11

A system as claimed in claim 9, further including identification means in the response means for adding to the write system status command information identifying the access path and the host system which gave the denial.

Claim 12

A system as claimed in claim 4, wherein each of the control units includes a single command input portion acting as the command input portions for all of the path devices within such control unit; each of the common command input portions including programmed means constituting the reconfigure request means and the communication means; and a plurality of peripheral units attached to the control units for communication therewith and each of the peripheral units including at least one of the peripheral devices and having a peripheral common command input portion for all of the devices within the respective peripheral unit as constituting the command input portions of the respective devices and including means for supplying reconfiguration requests received from the respective peripheral common command input portions to the communication means for relaying to the host system via one of the path devices in a one of the the access paths to the device being reconfigured from the host system.

Claim 14

In a method for selectively quiescing a device of a peripheral sub-system having a manual input portion from access by an attached host system of a data processing system and wherein the peripheral sub-system has a plurality of such devices; the steps of: generating in the peripheral sub-system a sub-system configuration table indicating all sub-system internal access paths to the devices for enabling access by the host system to the devices; supplying the sub-system configuration table to the host system and storing the sub-system configuration table in such host system; manually inserting into the peripheral sub-system a request to quiesce a one of the devices for temporarily preventing access to the one device by the host system; in the peripheral sub-system, generating a plurality of reconfiguration requests relating to each possible access path between the host system and the one device and sending all of the requests over the respective possible access paths to the host system; in the host system, receiving and analysing all of the received requests for determining permissibility of the requested quiescence, if the analysing indicates permitted quiescence, indicating such quiescence in all tables of the host system for the respective access paths and supplying an indication to the peripheral sub-system that the data processing system has been reconfigured enabling the quiescence; if the analysing indicates quiescence is not permissible, then sending a message to the sub-system that the quiescence is denied along with a reason for the denial; and in the sub-system, responding to all of the reconfiguration indications to isolate the device and indicating to the manual input portion that reconfiguration has been completed for permitting access to the device independently of the host system and responding to any one of the quiescence denials even with a number of reconfiguration indications being received for indicating to the manual input portion that reconfiguration has been denied.

Claim 15

In a method for selectively quiescing a device of a peripheral sub-system having a manual input portion from access by an attached host system of a data processing system and wherein the peripheral sub-system has a plurality of such devices; the steps of: generating in the peripheral sub-system a sub-system configuration table indicating all sub-system internal access paths to the devices for enabling access by the host system to the devices; supplying the sub-system configuration table to the host system and storing the sub-system configuration table in such host system; manually inserting into the peripheral sub-system a request to quiesce a one of the devices for temporarily preventing access to the one device by the host system; in the peripheral sub-system, generating a plurality of reconfiguration requests relating to each possible access path between the host system and the one device and sending all of the requests over the respective possible access paths to the host system; in the host system, receiving and analysing all of the received requests for determining permissibility of the requested quiescence, if the analysing indicates permitted quiescence, indicating such quiescence in all tables of the host system for the respective access paths and supplying an indication to the peripheral sub-system that the data processing system has been reconfigured enabling the quiescence; if the analysing indicates quiescence is not permissible, then sending a message to the sub-system that the quiescence is denied along with a reason for the denial; and in the sub-system, responding to all of the reconfiguration indications to isolate the device and indicating to the manual input portion that reconfiguration has been completed for permitting access to the device independently of the host system and responding to any one of the quiescence denials even with a number of reconfiguration indications being received for indicating to the manual input portion that reconfiguration has been denied.

Claim 16

A method as claimed in claim 13, wherein a plurality of access paths extend between the attached host system and the peripheral sub-system including a plurality of access paths within the peripheral sub-system such that the host system can through dynamic pathing access any of the devices through one or more of the access paths; further including the steps of: grouping the access paths into path groups such that a host request or command signal sent to the sub-system can be responded to over any of the accessed paths within a path group; and sending one reconfiguration request to the host system for all of the paths in each path group and sending a single request over each of the access path not a member of a given path group.

Claim 17

A method as claimed in claim 13 or claim 14, wherein the peripheral sub-system has unit devices at the end of each of the access paths with the unit devices being addressable by the host system and a plurality of path devices in the respective access paths; the steps of: varying off any of the devices including the path device unless a vary off of the path device removes a last path of access to a one of the unit devices.