Computer failure recovery and alert system

• US 5,956,475 A
• Filed: 12/18/1996
• Issued: 09/21/1999
• Est. Priority Date: 10/02/1992
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Emerson, Theodore F., Dow, Randolph O., Perez, Lazaro D., Stimac, Gary A., Burckhartt, David M.
• Primary Examiner(s): Palys, Joseph E.
• Application Number:
  US08/768,681
• Time in Patent Office: 1,007 Days
• Field of Search: 395/182.14, 395/182.18, 395/182.21, 395/185.01, 395/185.08, 395/183.12, 395/183.21, 395/185.1
• US Class Current: 714/23
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/1415 at system level
• CPC Class Codes: G06F 11/22 Detection or location of defective computer hardware by testing during standby operation or during idle time, e.g. start-up testing
• CPC Class Codes: G06F 11/2294 by remote test
• CPC Class Codes: G06F 9/4406 Loading of operating system
• CPC Class Codes: G11C 29/76 using address translation or modifications

Abstract

A computer system includes a timer which times out if the operating system does not periodically reset the timer. When the system fails and no longer resets the timer, the timer times out, and the computer is reset. The system performs its power on program and checks the memory array for bad memory blocks, which are mapped out of the memory. Next, the system alerts the operator of the failure using a pager. The system then reboots itself from a hard drive having two separate bootable partitions, one for the operating system in the first partition, and one for a diagnostics program in the second partition, so that an operator may diagnose and remedy the problem. The operator may set an indication of which partition to use for booting. The system further provides for remote access so that the operator may interact with the diagnostics program from a remote location.

Claims

1. A computer system, comprising:

a failure detection circuit operable to generate a reset signal when a failure is detected, wherein said reset signal resets the computer system;

a memory device capable of containing boot code, wherein said memory device includes a hard disk drive having a plurality of bootable partitions, one partition containing a normal operating system and another partition containing a diagnostic program; and

a processor coupled to said memory device and responsive to said reset signal for booting the computer system from said memory device when said reset signal is generated.

2. The computer system of claim 1, wherein said failure detection circuit includes:

a timer operable to load a countdown value and begin counting down from said countdown value, said timer operable to generate said reset signal when said timer reaches said countdown value.

3. The computer system of claim 2, wherein said failure detection circuit further includes:

a masking circuit operable to mask said reset signal generated by said timer when said masking circuit is enabled, said masking circuit being enabled after the computer system is powered on.

4. The computer system of claim 3, further comprising:

a software driver executable by said processor for disabling said masking circuit after determining a cause of the failure.

5. The computer system of claim 4, wherein said computer system is operable by a system operator wearing a pager, the computer system further comprising:

a modem coupled to said processor;

said software driver being operable to cause said modem to communicate with the pager in response to a failure.

6. The computer system of claim 1, further comprising:

a nonvolatile memory device operable to store a bootable partition selection; and

said processor being responsive to said bootable partition selection for booting the computer system to one of said hard disk drive partitions according to said selection.

7. The computer system of claim 6, further comprising:

means for allowing remote access to the computer system for receiving commands when the computer system is booted to said diagnostic program partition.

8. The computer system of claim 7, wherein said means for allowing remote access includes:

a modem;

means for indicating an incoming or outgoing access; and

means for completing said indicated access direction.

9. The computer system of claim 1, further comprising:

a diagnostic routine executable by said processor for testing the memory of the computer system in response to a failure;

said diagnostic routine capable of logging faults found during the memory testing; and

means for deallocating memory found to have faults during the memory testing.

10. A method of handling a failure in a computer system, the computer system including a hard disk drive having one or more bootable partitions and a nonvolatile memory device operable to store a bootable partition selector, the method comprising the computer implemented steps of:

(a) detecting a failure in the computer system;

(b) generating a reset signal when a failure is detected, said reset signal causing the computer system to reset; and

(c) booting the computer system in response to said reset signal, the booting step utilizing boot code stored in a bootable partition which has been selected based on the bootable partition selector stored in the nonvolatile memory device.

11. The method of claim 10, wherein step (a) further comprises the steps of:

(d) periodically initializing a timer while said computer system is operational;

(e) causing said timer to begin timing after step (d); and

(f) determining a failure has happened if said timer times out.

12. The method of claim 10, wherein step (b) further comprises the steps of:

(g) masking said reset signal after the computer system is power on; and

(h) selectably unmasking said reset signal if failure recovery is desired.

13. The method of claim 12, wherein after unmasking said reset signal, the method further comprises the steps of:

(i) analyzing the failure for a cause of the failure; and

(j) masking said reset signal after determining the cause of the failure.

14. The method of claim 10, wherein one partition contains a normal operating system and another partition contains a diagnostic program, the method further comprising the step of:

(m) causing the computer system to allow remote access when the computer system is booted to said diagnostic partition.

15. The method of claim 14, wherein the computer system includes a main memory, the method further comprising the steps of:

(n) testing the main memory after step (m);

(o) logging faults found during step (n); and

(p) deallocating a portion of main memory found to be faulty during step (n).

16. The method of claim 10, further comprising the step of:

(q) causing the computer system to communicate with a pager in response to the failure.