Method for reconfiguring containers without shutting down the system and with minimal interruption to on-line processing

• US 6,032,217 A
• Filed: 11/04/1997
• Issued: 02/29/2000
• Est. Priority Date: 11/04/1997
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Adaptec Incorporated (Steel Partners Holdings LP)
• Inventors: Arnott, Randy Marc
• Primary Examiner(s): Lee, Thomas C.
• Assistant Examiner(s): ELAMIN, ABDELMONIEM I
• Application Number:
  US08/964,356
• Time in Patent Office: 847 Days
• Field of Search: 710/1, 710/200, 711/152, 714/15, 714/5, 714/7
• US Class Current: 710/200
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

The system enables on-line container reconfiguration with minimal interference to the on-line processing by blocking all incoming I/O requests into the container drivers. The drivers queue the incoming I/O requests, continue to process all the preexisting I/O requests and signal the system upon completion. Upon receiving signals from all the container drivers with preexisting I/O requests, the system reconfigures the container tables as requested in the reconfiguration request. When the reconfiguration is complete, the system unblocks the blocked I/O requests and processes them and subsequent requests in accordance with the new configuration. By temporarily blocking the I/O requests and dynamically reconfiguring the container tables while the file system is still processing other I/O requests, the system performs on-line container reconfigurations with minimal interference with other on-line processing.

Claims

1. A method for reconfiguring containers in an I/O subsystem of a data processing system, the I/O subsystem executing I/O requests received from at least one application running on the system and directed to at least one container of the I/O subsystem, each container having a container driver adapted to process I/O requests received by the I/O subsystem, the I/O subsystem having an entry point for each container that references a container driver and the associated data structures for that container, each I/O request referencing a specific entry point, said method comprising the steps of:

maintaining a process count of I/O requests previously received by the I/O subsystem;

initiating a reconfiguration process by asserting a configuration flag in response to an I/O request to reconfigure the containers;

blocking all new I/O requests to the I/O subsystem in response to the initiated reconfiguration process;

decrementing the process count upon completing processing of the I/O requests previously received by the I/O subsystem;

sending a signal to the I/O subsystem when the process count equals zero;

reconfiguring the containers in the I/O subsystem in accordance with the reconfiguration process;

unblocking the blocked I/O requests; and

executing each unblocked I/O request by means of the specified entry point.

2. The method of claim 1 wherein the step of blocking comprises the step of queuing the new I/O requests to the I/O subsystem.

3. The method of claim 2 wherein the step of unblocking comprises the step of releasing each queued I/O request in the order received by the I/O subsystem to each container driver pointed to by the entry point in the I/O request.

4. The method of claim 3 wherein the step of reconfiguring comprises the step of changing the contents of the entry point of each reconfigured container to reference reconfigured data structures.

5. The method of claim 3 wherein the step of reconfiguring further comprises the steps of:

changing the contents of the entry point of each reconfigured container to reference a container driver for the reconfigured container; and

clearing the configuration flag.

6. A method for reconfiguring containers in an I/O subsystem of a data processing system, the I/O subsystem executing I/O requests received from at least one data processing application and directed to at least one container, the I/O subsystem including at least one container, each container having a container driver for processing I/O requests received by the I/O subsystem, the I/O subsystem having a separate entry point for each container, each entry point pointing to a specific container driver and to specific data structures for that container, each I/O request pointing to a specific entry point, said method comprising the steps of:

maintaining a process count of I/O requests currently in process at the container driver;

initiating a reconfiguration process;

blocking all new I/O requests pointing to the entry point for the container that is to be reconfigured;

decrementing the process count upon completing processing of the I/O requests previously received by the container that is to be reconfigured;

reconfiguring at least one container to satisfy a reconfiguration request in the reconfiguration process when the process count equals zero; and

unblocking the blocked I/O requests and executing them by means of the same entry points to which they pointed prior to reconfiguration.

7. The method of claim 6 including the steps of:

setting a system flag upon initiation of reconfiguration;

checking a state of the system flag before the container driver for the container to be reconfigured begins processing an incoming I/O request;

processing the incoming I/O request if the system flag is not set; and

blocking the incoming I/O request if the system flag is set.

8. A method for reconfiguring a container in an I/O subsystem of a data processing system, the I/O subsystem including a container manager and the container having a container driver for processing I/O requests received by the I/O subsystem, said method comprising the steps of:

maintaining a process count of I/O requests currently in process at the container driver;

asserting a configuration flag in response to issuance of a reconfiguration I/O request by an application to the container driver, the reconfiguration I/O request requesting reconfiguration of the container;

blocking new I/O requests directed to the container in response to assertion of the configuration flag;

decrementing the process count upon completion of processing of each I/O request currently in process at the container driver;

sending a completion signal to a container manager when the process count reaches zero;

executing a configuration process at the configuration manager in response to receiving the completion signal, the configuration process reconfiguring the container;

clearing the configuration flag;

unblocking the blocked I/O requests; and

directing the unblocked I/O requests to the container driver.