Patent Application
20120173653
1. Field of the Invention
The present invention relates to the management of virtual machines.
2. Background of the Related Art
In a cloud computing environment, a user is assigned a virtual machine somewhere in the computing cloud. The virtual machine provides the software operating system and has access to physical resources, such as input/output bandwidth, processing power and memory capacity, to support the user's application. Provisioning software manages and allocates virtual machines among the available computer nodes in the cloud. Because each virtual machine runs independent of other virtual machines, multiple operating system environments can co-exist on the same physical computer in complete isolation from each other.
Virtual machine management policies may be implemented by a provisioning manager application on a management node. For example, a management node of a multi-server chassis include a provisioning manager that provisions and migrates virtual machines to achieve some operational objective. Using the ability to migrate a virtual machine, the provisioning manager can manage the use of system resources. Still, the migration itself requires system resources and imparts a latency in the availability of the virtual machine while it is being copied from one server to another. These and other challenges threaten to limit the efficiency improvements that can be achieved through virtual machine migration.
One embodiment of the present invention provides a computer-implemented method for migrating a virtual machine. The virtual machine is initially operated on a first server, wherein the first server accesses the virtual machine image over a network at a memory location within fabric attached memory. The virtual machine is migrated from the first server to a second server by flushing data to the virtual machine image from cache memory associated with the virtual machine on the first server and providing the state and memory location of the virtual machine to the second server. The virtual machine may then operate on the second server, wherein the second server accesses the virtual machine image over the network at the same memory location within the fabric attached memory without copying the virtual machine image.
One embodiment of the present invention provides a computer-implemented method for migrating a virtual machine. The virtual machine is initially operated on a first server, wherein the first server accesses the virtual machine image over a network at a memory location within fabric attached memory, such as a memory subsystem attached with a computing subsystem through high speed network. The virtual machine is migrated from the first server to a second server by flushing data to the virtual machine image from cache memory associated with the virtual machine on the first server and providing the state and memory location of the virtual machine to the second server. The virtual machine may then operate on the second server, wherein the second server accesses the virtual machine image over the network at the same memory location within the fabric attached memory without copying the virtual machine image.
Various embodiments of the invention provide the advantage that the virtual machine image does not have to be copied. This reduces migration latency (i.e., the amount of time it takes to migrate a virtual machine and resume operation), conserves the use of memory, and eliminates the use of network bandwidth to move the virtual machine image. By providing the second server (i.e., the target server) with the state and memory location of the virtual machine, the second server is able to access the virtual machine image over the network and resume operation of the virtual machine using the original virtual machine image.
In one embodiment, a first hypervisor on the first server provides the state and memory location of the virtual machine, and a second hypervisor on the second server receives the state and memory location of the virtual machine. A provisioning manager, such as IBM's Active Energy Manager or and Director VM Control, initiates the migration.
In another embodiment, the virtual machine continues to operate on the first server during migration. This movement of a VM between servers while the VM continues to handle the workload is referred to as a “live migration.”
With reference now to the figures,
Computer 102 includes a processor unit 104 that is coupled to a system bus 106. Processor unit 104 may utilize one or more processors, each of which has one or more processor cores. A video adapter 108, which drives/supports a display 110, is also coupled to system bus 106. In one embodiment, a switch 107 couples the video adapter 108 to the system bus 106. Alternatively, the switch 107 may couple the video adapter 108 to the display 110. In either embodiment, the switch 107 is a switch, preferably mechanical, that allows the display 110 to be coupled to the system bus 106, and thus to be functional only upon execution of instructions (e.g., virtual machine provisioning program—VMPP 148 described below) that support the processes described herein.
System bus 106 is coupled via a bus bridge 112 to an input/output (I/O) bus 114. An I/O interface 116 is coupled to I/O bus 114. I/O interface 116 affords communication with various I/O devices, including a keyboard 118, a mouse 120, a media tray 122 (which may include storage devices such as CD-ROM drives, multi-media interfaces, etc.), a printer 124, and (if a VHDL chip 137 is not utilized in a manner described below) external USB port(s) 126. While the format of the ports connected to I/O interface 116 may be any known to those skilled in the art of computer architecture, in a preferred embodiment some or all of these ports are universal serial bus (USB) ports.
As depicted, the computer 102 is able to communicate with a software deploying server 150 via network 128 using a network interface 130. The network 128 may be an external network such as the Internet, or an internal network such as an Ethernet or a virtual private network (VPN).
A hard drive interface 132 is also coupled to the system bus 106. The hard drive interface 132 interfaces with a hard drive 134. In a preferred embodiment, the hard drive 134 communicates with a system memory 136, which is also coupled to the system bus 106. System memory is defined as a lowest level of volatile memory in the computer 102. This volatile memory includes additional higher levels of volatile memory (not shown), including, but not limited to, cache memory, registers and buffers. Data that populates the system memory 136 includes the operating system (OS) 138 and application programs 144 of the computer 102.
The operating system 138 includes a shell 140 for providing transparent user access to resources such as application programs 144. Generally, the shell 140 is a program that provides an interpreter and an interface between the user and the operating system. More specifically, the shell 140 executes commands that are entered into a command line user interface or from a file. Thus, the shell 140, also called a command processor, is generally the highest level of the operating system software hierarchy and serves as a command interpreter. The shell provides a system prompt, interprets commands entered by keyboard, mouse, or other user input media, and sends the interpreted command(s) to the appropriate lower levels of the operating system (e.g., a kernel 142) for processing. Note that while the shell 140 is a text-based, line-oriented user interface, the present invention will equally well support other user interface modes, such as graphical, voice, gestural, etc.
As depicted, the operating system 138 also includes kernel 142, which includes lower levels of functionality for the operating system 138, including providing essential services required by other parts of the operating system 138 and application programs 144, including memory management, process and task management, disk management, and mouse and keyboard management.
The application programs 144 include an optional renderer, shown in exemplary manner as a browser 146. The browser 146 includes program modules and instructions enabling a world wide web (WWW) client (i.e., computer 102) to send and receive network messages to the Internet using hypertext transfer protocol (HTTP) messaging, thus enabling communication with software deploying server 150 and other described computer systems.
Application programs 144 in the system memory of the computer 102 (as well as the system memory of the software deploying server 150) also include a virtual machine provisioning program (VMPP) 148. The VMPP 148 includes code for implementing the processes described below, including those described in
Optionally also stored in the system memory 136 is a VHDL (VHS IC hardware description language) program 139. VHDL is an exemplary design-entry language for field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), and other similar electronic devices. In one embodiment, execution of instructions from VMPP 148 causes VHDL program 139 to configure VHDL chip 137, which may be an FPGA, ASIC, etc.
In another embodiment of the present invention, execution of instructions from the VMPP 148 results in a utilization of the VHDL program 139 to program a VHDL emulation chip 152. The VHDL emulation chip 152 may incorporate a similar architecture as described above for VHDL chip 137. Once VMPP 148 and VHDL program 139 program the VHDL emulation chip 152, VHDL emulation chip 152 performs, as hardware, some or all functions described by one or more executions of some or all of the instructions found in VMPP 148. That is, the VHDL emulation chip 152 is a hardware emulation of some or all of the software instructions found in VMPP 148. In one embodiment, VHDL emulation chip 152 is a programmable read only memory (PROM) that, once burned in accordance with instructions from VMPP 148 and VHDL program 139, is permanently transformed into a new circuitry that performs the functions needed to perform the process described below in
The hardware elements depicted in computer 102 are not intended to be exhaustive, but rather are representative to highlight essential components required by the present invention. For instance, computer 102 may include alternate memory storage devices such as magnetic cassettes, digital versatile disks (DVDs), Bernoulli cartridges, and the like. These and other variations are intended to be within the spirit and scope of the present invention.
As shown in
Note that chassis backbone 206 is also coupled to a network 216, which may be a public network (e.g., the Internet), a private network (e.g., a virtual private network or an actual internal hardware network), etc. Network 216 permits a virtual machine workload 218 to be communicated to a management interface 220 of the blade chassis 202. This virtual machine workload 218 is a software task whose execution is requested on any of the VMs within the blade chassis 202. The management interface 220 then transmits this workload request to a provisioning manager/management node 222, which is hardware and/or software logic capable of configuring VMs on fabric attached memory 240 to execute the requested software task. In essence the virtual machine workload 218 manages the overall provisioning of VMs by communicating with the blade chassis management interface 220 and provisioning management node 222. Then this request is further communicated to the virtual machine provisioning program 148 in the generic computer system (See
The global provisioning manager preferably keeps track of the VMs of multiple chassis or multiple rack configurations. If the local provisioning manager is able, that entity will be responsible for migrating VMs within the chassis or rack and send that information to the global provisioning manager. The global provisioning manager would be involved in migrating VMs among multiple chassis or racks, and perhaps also instructing the local provisioning management to migrate certain VMs. For example, the global provisioning manager 232 may build and maintain a table containing the same VM data as the local provisioning manager 222, except that the global provisioning manager would need that data for VMs in each of the chassis or racks in the multiple chassis or multiple rack system. The tables maintained by the global provisioning manager 232 and each of the local provisioning managers 222 would be kept in sync through ongoing communication with each other. Beneficially, the multiple tables provide redundancy that allows continued operation in case one of the provisioning managers stops working.
Fabric attached memory 240 is also accessible to each of the blade servers 204a-n in the blade chassis 202 via input/output over the network 216. Accordingly, a virtual machine image associated with each virtual machine 208a-n on a first blade server 204a, as well as each virtual machine 210a-n on a second or further blade server 204n, is stored on the fabric attached memory 240.
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As will be appreciated by one skilled in the art, the present invention may be embodied as a system, method or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product embodied in one or more computer-readable storage medium having computer-usable program code stored thereon.
Any combination of one or more computer usable or computer readable storage medium(s) may be utilized. The computer-usable or computer-readable storage medium may be, for example but not limited to, an electronic, magnetic, electromagnetic, or semiconductor apparatus or device. More specific examples (a non-exhaustive list) of the computer-readable medium include: a portable computer diskette, a hard disk, random access memory (RAM), read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, or a magnetic storage device. The computer-usable or computer-readable storage medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. In the context of this document, a computer-usable or computer-readable storage medium may be any storage medium that can contain or store the program for use by a computer. Computer usable program code contained on the computer-usable storage medium may be communicated by a propagated data signal, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted from one storage medium to another storage medium using any appropriate transmission medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc.
Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
