Abstract:
A client computer system is provided with two operating systems, one of which is a user operating system (UOS) and the other of which is a service operating system (SOS), and a hypervisor. In the event of a hang in the first operating system, the second operating system remains active, out of the awareness of the user of the system, and has reporting and command response capabilities beyond those of prior technology.

Description:
FIELD AND BACKGROUND OF INVENTION  
       [0001]    This invention relates to apparatus and methods by which error reporting and management in computer systems are facilitated. More particularly, the invention relates to expanding the capabilities of known techniques for such messaging. 
         [0002]    It has been known heretofore that an end user or client computer system, as with other devices used in network technologies, can be configured and enabled to report to a management console problems in operation and received from the console messages commanding certain actions. Such capabilities have, however, suffered from certain limitations. Because of the reliance of some of these messaging standards upon processor activity and the reliance of client computer systems on functionality enabled by operating systems, the reports possible and commands accepted when an operating system fails have been severely restricted to events monitored by sensors in the system and commands to which the system could respond without necessity of an operating system being active. 
       SUMMARY OF THE INVENTION  
       [0003]    With the foregoing in mind, it is one purpose of this invention to expand the capabilities of a client computer system with regard to error reporting and command response. In pursuing this purpose, the present invention contemplates that technologies be combined in a new way to provide for use of a system central processing unit (CPU) even in circumstances where the usual operating system has failed or become corrupted. 
         [0004]    In accordance with this invention, a client computer system is provided with two operating systems, one of which is a user operating system (hereinafter sometimes UOS) and the other of which is a service operating system (hereinafter sometimes SOS). In the event of a hang in the first operating system, the second operating system remains active, out of the awareness of the user of the system, and has reporting and command response capabilities beyond those of prior technology. 
     
     
       BRIEF DESCRIPTION OF DRAWINGS  
         [0005]    Some of the purposes of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which: 
           [0006]      FIG. 1  is a perspective view of an illustrative embodiment of a computer system; 
           [0007]      FIG. 2  is a block diagram representation of an illustrative computer system such as the system of  FIG. 1 ; 
           [0008]      FIG. 3  is a block diagram representation of certain hardware and software elements embodying the present invention; and 
           [0009]      FIG. 4  is an illustration of one form of computer readable media on which the program elements of the present invention may ne distributed. 
       
    
    
     DETAILED DESCRIPTION OF INVENTION  
       [0010]    While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the present invention is shown, it is to be understood at the outset of the description which follows that persons of skill in the appropriate arts may modify the invention here described while still achieving the favorable results of the invention. Accordingly, the description which follows is to be understood as being a broad, teaching disclosure directed to persons of skill in the appropriate arts, and not as limiting upon the present invention. 
         [0011]      FIG. 1  illustrates a typical computer workstation, here a personal computer system  10 . The system includes a central processor, memory accessible to the processor for storing data including programs to be executed, a display  11 , input devices including a keyboard  12  and a pointing device (here shown as a mouse  13 ), a digital data storage device (commonly a hard disk drive) and output devices including a network interface, often known as a NIC. The NIC may implement network connectivity by a wired connection such as an Ethernet connection or by a wireless connection (indicated at  14  in  FIG. 1 ) such as one of the IEEE 802.11 protocols. Such computer systems come in a variety of configurations, some known as notebook systems, others as desktop or deskside systems, some known as servers, and some known as “thin clients”. The same technology appears in what are known as handheld computer systems (some of which are also known as PDAs or Personal Digital Assistants) and in certain telephone instruments such as cellular or smart telephones. The present invention may find usefulness with many such systems, depending upon the limitations of each such system, and it is to be understood that the choice of one type of such system for illustration is in no way limiting upon the implementation of this invention. Persons familiar with the arts of computer technology will easily recognize the scope of applicability of what is here described and illustrated. It is contemplated that the principal usefulness will be with user workstations connected with networks, also here called client systems. 
         [0012]      FIG. 2  is one illustrative embodiment of a computer system which may function as the system  10  of  FIG. 1  and which includes a system processor or CPU  20 , coupled to a Read-Only Memory (ROM)  21  and a system memory  22  by a processor bus  24 . System processor  20  is a general-purpose processor that executes boot code stored within ROM  21  at power-on and thereafter processes data under the control of an operating system and application software stored in system memory  22 . System processor  20  is coupled via the processor bus  24  and a host bridge  25  to a Peripheral Component Interconnect (PCI) local bus  26 . 
         [0013]    The PCI local bus  26  supports the attachment of a number of devices, including adapters and bridges. Among these devices is a network adapter or NIC  28 , which interfaces the computer system  10  to a LAN (wired or wireless), and graphics adapter  29 , which interfaces the computer system  10  to the display  11 . Communication on the PCI local bus  26  is governed by a local PCI controller  30 , which is in turn coupled to non-volatile random access memory (NVRAM)  31  via a memory bus  32 . Local PCI controller  30  can be coupled to additional buses and devices via a second host bridge  34 . 
         [0014]    Computer system  10  further may include an Industry Standard Architecture (ISA) bus  35 , which is coupled to the PCI local bus  26  by an ISA bridge  36 . Coupled to the ISA bus  35  is an input/output (I/O) controller  38 , which controls communication between computer system  10  and attached peripheral devices such as a keyboard  12 , mouse  13 , and a disk drive  39  on which software is stored as digital data. In addition, I/O controller  38  supports external communication by computer system  10  via serial and parallel ports. Alternatively, more recently designed systems may use a PCI Express service for such functions as graphics. 
         [0015]    A client system such as the system  10  will have a user operating system (UOS, indicated at  40  in  FIG. 3 ) which conventionally may be a product of Microsoft Corporation or of a Linux distributor. The UOS will be executable computer code stored on the storage device  38  of the system accessibly to the system CPU  20  which, when executing on the computer system, instantiates an operating system. Underlying the UOS is a hypervisor layer  41  interposed between the UOS  40  and the hardware of the system  10 . 
         [0016]    “Hypervisor” is a term of art which has been used to refer to a virtual machine monitor (VMM)—a thin piece of software that runs directly on top of the hardware and virtualizes all the hardware resources of the machine. Since the virtual machine monitor&#39;s interface is the same as the hardware interface of the machine, an operating system cannot determine the presence of the VMM. Consequently, when the hardware interface is one-for-one compatible with the underlying hardware, the same operating system can run either on top of the virtual machine monitor or on top of the raw hardware. It is then possible to run multiple instances of operating systems or merely instances of operating system kernels. The operating systems will share resource access. Each instance is referred to as a virtual machine. The operating system can be replicated across virtual machines or distinctively different operating systems can be used for each virtual machine. In any case, the virtual machines are entirely autonomous and depend on the virtual machine monitor for access to the hardware resources such as hardware interrupts. 
         [0017]    The interested reader is referred to the literature, which describes virtual machines and virtual machine monitors which arose out of the need to run applications written for different operating systems concurrently on a common hardware platform, or for the full utilization of available hardware resources. Virtual machine monitors were the subject of research since the late 1960&#39;s and came to be known as the “Virtual Machine Monitor” (VMM). Persons of ordinary skill in the art are urged to refer to, for example, R. P. Goldberg, “Survey of Virtual Machine Research,” IEEE Computer, Vol. 7, No. 6, 1974. During the 1970&#39;s, as a further example, International Business Machines Corporation adopted a virtual machine monitor for use in its VM/370 system. 
         [0018]    In accordance with the present invention, the presence of the hypervisor layer  31  enables the instantiation of a second operating system in the computer system  10 , indicated at  42  in  FIG. 3  and here identified as a service operating system or SOS. The SOS  42  is used for client manageability and may be, as the UOS may be, a product of Microsoft Corporation or of a Linux distributor. 
         [0019]    The present invention contemplates that the executable computer code stored on said storage device  38  accessibly to the computer system CPU  20 , when executing on the computer system, instantiates first and second operating systems (the UOS and SOS) and a hypervisor which enables the first and second operating systems to function simultaneously. One of the operating systems controls the physical network interface or NIC  28 . The hypervisor  41  provides alert standard format services through the SOS and NIC which exchanges messages with a management console. 
         [0020]    Mention was made herein above of industry standard protocols for exchange of information between networked devices and management consoles. One such standard which of particular significance to this invention is known as the Alert Standard Format or ASF. Details are available in a white paper published by the Distributed Management Task Force and found at http://www.dmff.org/education/technote_ASF.pdf. This standard in a normal implementation allows a client system to notify a management console of limited error conditions when in an operating system absent condition. That is, when the normal (or UOS) operating system in a client system is non-functional, the ASF allows limited data communication through an enabled NIC and limited response to a certain vocabulary of commands. 
         [0021]    The present invention contemplates a substantial enhancement of the capabilities of such notifications and responses. More particularly, by providing code instantiating first and second operating systems and a hypervisor layer and providing that the SOS is outside the attention of a user of said system, the present invention allows full access to the system CPU  20  during absence or failure of the UOS and thus full reporting of the system conditions and full access for responding to a wide range of management console commands. 
         [0022]    Here, the SOS controls the physical NIC, and the UOS functions through a virtual NIC. This enables the management console, if needed, to gather detailed reports on the state of the client system  10  and issue commands to perform and necessary diagnostics or corrections. 
         [0023]    It will be apparent that this invention is implemented in hardware and in software-apparatus and methods. The methods of this invention include providing a computer system with executable computer code which, when executing on said computer system, instantiates first and second operating systems and a hypervisor which enables said first and second operating systems to function simultaneously; and providing in the hypervisor alert standard format services which exchange messages with a management console. Further, the methods include producing computer executable program code, storing the produced program code on a computer readable medium; and providing the program code to be deployed to and executed on a computer system to execute instructions as described immediately above. Such code may be distributed by depositing a copy on a computer readable medium such s a diskette  40  shown in  FIG. 4 . The choice of a diskette for illustration is simply that—an illustration—as such media come in a variety of forms including hard drives, flash memory and other devices. Distribution may be by loading the code onto such a medium through a network distribution. 
         [0024]    In the drawings and specifications there has been set forth a preferred embodiment of the invention and, although specific terms are used, the description thus given uses terminology in a generic and descriptive sense only and not for purposes of limitation.