Title: Virtualized logical server cloud providing non-deterministic allocation of logical attributes of logical servers to physical resources
Abstract: A virtualized logical server cloud that enables logical servers to exist independent of physical servers that instantiate the logical servers. Servers are treated as logical resources in order to create a logical server cloud. The logical attributes of a logical server are non-deterministically allocated to physical resources creating a cloud of logical servers over the physical servers. Logical separation is facilitated by the addition of a server cloud manager, which is an automated multi-server management layer. Each logical server has persistent attributes that establish its identity. Each physical server includes or is coupled to physical resources including a network resource, a data storage resource and a processor resource. At least one physical server executes virtualization software that virtualizes physical resources for logical servers. The server cloud manager maintains status and instance information for the logical servers including persistent and non-persistent attributes that link each logical server with a physical server.
Patent Number: 6,880,002 Issued on 04/12/2005 to Hirschfeld, et al.
| Inventors:
|
Hirschfeld; Robert A. (Metairie, LA);
McCrory; Dave D. (Destrehan, LA)
|
| Assignee:
|
Surgient, Inc. (Austin, TX)
|
| Appl. No.:
|
100216 |
| Filed:
|
March 18, 2002 |
| Current U.S. Class: |
709/223; 709/227; 709/250; 709/225; 709/229; 710/313; 710/72 |
| Intern'l Class: |
G06F 015//17.3 |
| Field of Search: |
710/305-306,311-317,62-54,72,7,8,10
709/200-203,223-231,248-250,328-331
718/100,101,106
707/100-103
|
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|
Primary Examiner: Myers; Paul R.
Assistant Examiner: Phan; Raymond N
Attorney, Agent or Firm: Stanford; Gary R.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION(S)
The present application is based on U.S. Provisional Patent Application
entitled "Virtualized Logical Server Cloud", Ser. No. 60/317,294, filed
Sep. 5, 2001, which is hereby incorporated by reference in its entirety.
Claims
What is claimed is:
1. A virtualized logical server cloud, comprising:
a plurality of logical servers, each having persistent attributes that
establish its identity;
a network system;
a plurality of physical servers, each coupled to physical resources
including a network resource for interfacing the network system, a data
storage resource and a processor resource, and each physical server
executing virtualization software that virtualizes one or more of the
physical resources for logical servers that are linked to that physical
server; and
a server cloud manager, interfaced to the plurality of physical servers,
that establishes and maintains status and instance information for the
plurality of logical servers including the persistent and non-persistent
attributes that link each logical server with a physical server.
2. The virtualized logical server cloud of claim 1, wherein the data
storage resource comprises a non-volatile storage resource and volatile
memory resource.
3. The virtualized logical server cloud of claim 1, further comprising:
a user database, coupled to the server cloud manager, that includes mapping
information between users, the plurality of logical servers and the
plurality of physical servers; and
the server cloud manager including a user interface that enables access and
control of any one or more of the physical and logical servers by users;
wherein the server cloud manager receives user credential information via
the user interface and provides control and access of a corresponding one
or more of the physical and logical servers.
4. The virtualized logical server cloud of claim 1, further comprising:
each logical server incorporating a keyboard/video/mouse (KVM) resource;
the virtualization software of each physical server implementing a virtual
KVM function to enable access to each KVM resource of each logical server
linked to that physical server; and
the server cloud manager providing KVM redirection between a user KVM
client and the virtual KVM function of each physical server.
5. The virtualized logical server cloud of claim 1, wherein the persistent
attributes include a media access control (MAC) address, a boot disk
image, a system identifier, a processor type and access credentials.
6. The virtualized logical server cloud of claim 1, wherein the
non-persistent attributes include processor resource information, memory
resource information, keyboard/video/mouse (KVM) resources and disk
redundancy level.
7. The virtualized logical server cloud of claim 1, wherein each logical
server executes a separate operating system.
8. The virtualized logical server cloud of claim 1, further comprising a
shared storage system coupled to the network system.
9. The virtualized logical server cloud of claim 1, further comprising:
each physical server including at least one physical server agent that is
controlled by the server cloud manager in order to manage physical
resources for each logical server linked to the physical server.
10. The virtualized logical server cloud of claim 1, further comprising:
each logical server including a logical server agent that extends control
of a corresponding logical server to the server cloud manager.
11. The virtualized logical server cloud of claim 1, further comprising:
each physical server including at least one physical server agent that is
controlled by the server cloud manager in order to manage physical
resources for each logical server linked to the physical server;
each logical server including a logical server agent that extends control
of each logical server to the server cloud manager; and
the server cloud manager interfacing and controlling each physical server
agent and each logical server agent.
12. The virtualized logical server cloud of claim 1, wherein the server
cloud manager orchestrates a move procedure for moving a logical server
from a first physical server to a second physical server, and wherein the
move procedure includes copying a disk image from the first physical
server to the second physical server, copying logical server configuration
from the first physical server to the second physical server, and
remapping keyboard/video/mouse (KVM) functions from the first physical
server to the second physical server.
13. The virtualized logical server cloud of claim 1, further comprising:
a physical server agent operating on a physical server;
a virtual keyboard/video/mouse (KVM) function implemented by the
virtualization software of the physical server;
the server cloud manager instructing the physical server agent to replicate
a logical server on the physical server, and after the logical server is
activated, redirecting a KVM client to the virtual KVM function;
the physical server agent, as controlled by the server cloud manager,
retrieving and locally storing a logical server template, creating logical
server configuration information from the logical server template,
activating a logical server from the logical server configuration
information, and relaying instructions from the server cloud manager to a
logical server agent of the activated logical server; and
the logical server agent completing activation of the logical server via
commands from the server cloud manager.
14. The virtualized logical server cloud of claim 1, wherein the server
cloud manager operates at a maximum security level with administrative
rights over logical server administrative access and multiple physical
server administrative access to enable logical server instancing.
15. The method of claim 1, wherein said server cloud manager comprises a
peer to peer application distributed among said plurality of physical
servers.
16. The virtualized logical server cloud of claim 4, wherein the server
cloud manager provides KVM mapping information to the user KVM client that
enables direct access to a selected logical server by the user KVM client.
17. The virtualized logical server cloud of claim 4, wherein the server
cloud manager comprises:
a KVM service that interfaces a user KVM client; and
a KVM client, interfaced to the KVM service and a virtual KVM function of a
physical server, that maps KVM functions between the KVM service and the
virtual KVM function.
18. The virtualized logical server cloud of claim 5, wherein the persistent
attributes further include semi-persistent attributes including an
internet protocol (IP) address, a logical name, a server cloud manager
identifier, user account information, a non-boot disk image and network
connections.
19. The virtualized logical server cloud of claim 8, wherein the shared
storage system stores at least one logical server template that is
configured to enable replication of a logical server on a physical server.
20. The virtualized logical server cloud of claim 9, wherein the physical
server agent runs as a service on an operating system of the physical
server.
21. The virtualized logical server cloud of claim 9, wherein each physical
server agent is capable of controlling physical server functions and
associated physical resources via interfaces to virtualization software of
a corresponding physical server.
22. The virtualized logical server cloud of claim 10, wherein at least one
logical server agent runs as a service on an operating system of the
corresponding logical server.
23. The virtualized logical server cloud of claim 12, wherein the move
procedure includes remapping network requests for the moved logical server
from the first physical server to the second physical server.
24. The virtualized logical server cloud of claim 14, wherein said logical
server instancing includes moving a logical server from a first physical
server to a second physical server.
25. A server cloud management system that virtualizes a plurality of
logical servers of a plurality of physical servers into a logical server
cloud, comprising:
virtualization software, executed on each physical server, that enables
linkage of logical servers with the physical servers;
an attribute database that maintains status and instance information for
each of the plurality of logical servers including persistent and
non-persistent attributes of each logical server;
a user database that includes mapping information between users, the
plurality of logical servers and the physical servers;
a user interface that establishes a portal for users and that receives user
credential information; and
a server cloud manager, interfaced to the virtualization software, the
attribute database, the user database and the user interface, that
provides access to and control of a logical server by a user session from
which valid user credential information is received.
26. The server cloud management system of claim 25, further comprising:
each physical server executing a physical server agent, interfaced to the
server cloud manager, that enables management of physical resources for
each logical server linked to a corresponding physical server.
27. The server cloud management system of claim 25, further comprising:
each logical server executing a logical server agent, interfaced to the
server cloud manager, that enables management and control of logical
attributes of the logical server by the server cloud manager.
28. The server cloud management system of claim 25, wherein the server
cloud manager operates at a maximum security level with administrative
rights over logical server administrative access and multiple physical
server administrative access to enable logical server instancing.
29. A method of virtualizing a plurality of logical servers into a logical
server cloud linked to a plurality of physical servers, comprising:
providing a virtual keyboard/video/mouse (KVM) function on each physical
server for mapping KVM information to logical servers linked to the
physical server;
maintaining attributes of each logical server by a server cloud manager
interfaced to the plurality of physical servers, the attributes
establishing an identity of and defining resources for each logical
server;
mapping, by the server cloud manager, each logical server with a physical
server and user information;
forwarding, by the server cloud manager, KVM information between remote
clients and the virtual KVM functions of each physical server; and
managing, by the server cloud manager via a physical server agent, physical
resources of a physical server on behalf of each logical server linked to
that physical server.
30. The method of claim 29, further comprising:
managing, by the server cloud manager via a logical server agent executing
on a logical server, logical attributes of the logical server.
31. The method of claim 29, further comprising moving a logical server from
a first physical server to a second physical server, including copying a
disk image from the first physical server to the second physical server,
copying a logical server configuration from the first physical server to
the second physical server, and remapping KVM functions from the first
physical server to the second physical server.
32. The method of claim 31, wherein said moving further comprises remapping
network requests for the moved logical server from the first physical
server to the second physical server.
33. The method of claim 29, further comprising replicating a logical server
on a physical server, including retrieving and storing a logical server
template on the physical server, creating logical server configuration
information from the logical server template, activating a logical server
from the logical server configuration information, linking a logical
server agent on the activated logical server with the server cloud
manager, and redirecting a KVM client to the virtual KVM function of the
physical server.
34. The method of claim 33, wherein said replicating further comprises
creating a unique identity for the replicated logical server.
35. The method of claim 33, wherein said replicating further comprises
mapping network requests for the replicated logical server.
Description
FIELD OF THE INVENTION
The present invention relates to virtualization and server technology, and
more particularly to a virtualized logical server cloud that includes
logical servers that are non-deterministically linked to physical servers
and that may exist independent of specific physical servers.
DESCRIPTION OF RELATED ART
There are many situations in which it is desired to lease one or more
server computer systems on a short or long-term basis. Examples include
educational or classroom services, demonstration of software to potential
users or buyers, website server applications, etc. The servers may be
pre-configured with selected operating systems and application software as
desired. Although physical servers may be leased and physically delivered
for onsite use, servers may also be leased from a central or remote
location and accessed via an intermediate network system, such as the
Internet. The primary considerations for remote access include the
capabilities of the remote access software and the network connection or
interface.
Remote access technology is known and many variations exist, such as
Microsoft Terminal Server, Citrix MetaFrame, Symantec pcAnywhere, VMware
Remote Console, etc. In general, local client software operates on a
client computer that enables communication with server software operating
on a server computer. Generally, the client software provides keyboard and
mouse commands and receives video and audio information and there is
little or no local client processing necessary. It is often desired to
share a single physical server among multiple users to more efficiently
utilize server resources. Many remote access systems enable multiple
access by simultaneously activating separate user sessions. Although some
files may be shared, other files or directories or even disk drives may
have permission-based attributes so that only authorized persons have
access. The same may be true for other physical or software resources
existing on or coupled to the physical server. Although multiple access to
a single physical server has many benefits, it may be desired to provide a
greater degree of isolation between or independence among the users for a
variety of reasons, such as, for example, improved security. Also, each
user may be detrimentally affected by activities of or problems caused by
one or more other users. If any user causes accidental or intentional
shutdown of the physical computer or any physical resources associated
therewith, or uploads a virus or the like, all users may be detrimentally
affected.
One solution is the use of virtualization technology that enables multiple
logical servers to operate on a single physical computer. Previously,
logical servers were tied directly to physical servers because they relied
on the physical server's attributes and resources for their identity.
Virtualization technology weakened this restriction by allowing multiple
logical servers to override a physical server's attributes and share its
resources. Virtualization technology is available from several companies,
including VMware, Connectix, Compaq and Ensim. Each logical server
operates substantially independent of other logical servers and provides
virtual isolation among users.
Although virtualization weakened the link between logical and physical
servers, logical servers were still bound or otherwise deterministically
linked to a specific physical server. The user had to be aware of and have
specific information about the underlying physical server to access the
logical servers. For example, the user had to provide specific information
of the physical server, such as an internet protocol (IP) address or
server name and a port number. The user had to further supply a correct
uniform resource locator (URL) or pathname to a selected logical server
linked to that physical server along with the corresponding user
credentials, such as username and password. If any of the access
information was input incorrectly, access was denied. A user having
permission to access multiple logical servers had to know the specific
access information for each including the physical server information.
Thus, if two different logical servers were located on two different
physical servers, the user had to know the access information for each,
including the specific access information for each physical server. If the
site administrator managing the physical servers attempted to move the
user from one logical server to another logical server located on a
different physical server, the user had to be informed of the new access
information even if the two logical servers were otherwise identical.
Also, if a physical server crashed or became disabled, all of the
associated logical servers were inaccessible indefinitely until the
physical server was repaired or replaced and brought back online.
Clustering technology is known but is also deterministic. In particular,
clustered resources interact within a predetermined and common
configuration to change physical resources. Clustering does not solve the
problem of isolating logical servers from the underlying physical system.
Clustering solves a different problem by employing two or more systems
that work together, and generally refers to multiple computer systems that
are linked together in order to handle variable workloads or to provide
continued operation in the event one fails. A cluster of computer systems
provides fault tolerance and/or load balancing. Fault tolerance ensures
that one or more systems are still available in the event any one system
fails. Load balancing distributes the workload over multiple systems.
It is desired to completely separate logical servers from physical servers
so that there is no permanent tie between physical and logical resources.
Such separation would allow for physical servers to act as a pool of
resources supporting logical servers, so that a logical server may be
reallocated to a different physical server without users experiencing any
change in access approach even during reallocation. It is desired to
remove the requirement of pre-allocation of physical resources prior to a
physical resource change as is required by clustering.
SUMMARY OF THE PRESENT INVENTION
A virtualized logical server cloud according to an embodiment of the
present invention includes a plurality of logical servers, a network
system, a plurality of physical servers and a server cloud manager. Each
logical server has persistent attributes that establish its identity. Each
physical server is coupled to physical resources including a network
resource for interfacing the network system, and each physical server
includes a data storage resource and a processor resource. The data
storage resource may include both volatile and non-volatile resources.
Each physical server executes virtualization software that virtualizes
physical resources for logical servers linked to that physical server. The
server cloud manager establishes and maintains status and instance
information for the logical servers including the persistent and any
non-persistent attributes that link each logical server with a physical
server.
The virtualized logical server cloud may include a user database that
includes mapping information between users, the logical servers and the
physical servers. The server cloud manager may include a user interface
that enables access and control of any one or more of the physical and
logical servers by users. The server cloud manager receives user
credential information via the user interface and provides control and
access of one or more of the physical and logical servers employing the
user database.
Each logical server may incorporate a KVM resource. The virtualization
software of each physical server may implement a virtual KVM function to
enable access to each KVM resource of each logical server linked to that
physical server. The SCM provides KVM redirection between a user KVM
client and the virtual KVM function of each physical server. In one
configuration, the server cloud manager provides KVM mapping information
to the user KVM client to enable direct access to a selected logical
server by the user KVM client. Alternatively, the server cloud manager
includes a KVM service and a KVM client. The KVM service interfaces a user
KVM client and the manager KVM client maps KVM functions between the KVM
service and the virtual KVM function.
Examples of persistent attributes include a media access control (MAC)
address, a boot disk image, a system identifier, a processor type and
access credentials. The persistent attributes may further include
semi-persistent attributes including an internet protocol (IP) address, a
logical name, a server cloud manager identifier, user account information,
a non-boot disk image and network connections. Examples of non-persistent
attributes include processor resource information, memory resource
information, KVM resources and disk redundancy level.
A shared storage system may be provided and coupled to the network system.
The shared storage system may store one or more logical server templates
that are each configured to enable replication of a logical server on a
physical server.
Each physical server may include at least one physical server agent that is
controlled by the server cloud manager in order to manage physical
resources for each logical server linked to a physical server. In one
embodiment, the physical server agent runs as a service on an operating
system of the physical server. Each physical server agent is capable of
controlling physical server functions and associated physical resources
via interfaces to virtualization software of the physical server. Each
logical server may include a logical server agent that extends control of
a corresponding logical server to the server cloud manager. The logical
server agent may run as a service on an operating system of the
corresponding logical server, where each logical server may execute a
separate operating system. The server cloud manager interfaces and
controls each physical server agent and each logical server agent.
At least one advantage of a virtualized logical server cloud according to
an embodiment of the present invention is that each logical server may be
non-deterministically linked to a physical server over time. For example,
the server cloud manager may orchestrate a move procedure to move a
logical server from a first physical server to a second physical server.
The move procedure includes copying a disk image from the first physical
server to the second physical server, copying logical server configuration
from the first physical server to the second physical server, and
remapping KVM functions from the first physical server to the second
physical server. The move procedure may further include remapping network
requests for the moved logical server from the first physical server to
the second physical server. The original logical server may be suspended,
deactivated, deleted or otherwise placed in standby mode.
The server cloud manager may instruct a physical server agent to replicate
a logical server on the underlying physical server. Replication involves
activation of a new logical server in a server cloud. After the replicated
logical server is activated, the server cloud manager redirects a KVM
client to the virtual KVM function. The physical server agent, as
controlled by the server cloud manager during a replication procedure,
retrieves and locally stores a logical server template, creates logical
server configuration information from the logical server template,
activates a logical server from the logical server configuration
information, and relays instructions from the server cloud manager to a
logical server agent of the activated logical server. The logical server
agent completes activation of the logical server via commands from the
server cloud manager.
The server cloud manager may operate at a maximum security level with
administrative rights over logical server administrative access and
multiple physical server administrative access to enable logical server
instancing. Logical server instancing includes, for example, moving a
logical server from a first physical server to a second physical server.
A server cloud management system according to an embodiment of the present
invention virtualizes a plurality of logical servers of a bank of physical
servers into a logical server cloud. The system includes virtualization
software, an attribute database, a user database, a user interface and a
server cloud manager. The virtualization software is executed on at least
one physical server and enables linkage of logical servers with the
physical server. The attribute database maintains status and instance
information for each of the plurality of logical servers including
persistent and non-persistent attributes of each logical server. The user
database includes mapping information between users, the plurality of
logical servers and the physical servers. The user interface establishes a
portal for users and receives user credential information. The server
cloud manager provides access and control of a logical server by a user
session from which valid user credential information is received.
A method of virtualizing a plurality of logical servers into a logical
server cloud linked to a plurality of physical servers according to an
embodiment of the present invention includes providing a virtual KVM
function on each physical server for mapping KVM information to logical
servers linked to the physical server, maintaining attributes of each
logical server by a server cloud manager interfaced to the plurality of
physical servers, the attributes establishing an identity of and defining
resources for each logical server, mapping, by the server cloud manager,
each logical server with a physical server and user information,
forwarding, by the server cloud manager, KVM information between remote
clients and the virtual KVM functions of each physical server, and
managing, by the server cloud manager via a physical server agent,
physical resources of a physical server on behalf of each logical server
linked to that physical server.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained when the
following detailed description of embodiments of the invention is
considered in conjunction with the following drawings, in which:
FIG. 1 is an overview block diagram illustrating a virtualized logical
server cloud implemented according to an embodiment of the present
invention including a server cloud manager (SCM).
FIG. 2 is a block diagram of the virtualized logical server cloud of FIG. 1
illustrating relationships between the logical servers of a logical server
cloud, physical servers, a shared network and the SCM.
FIG. 3 is a block diagram of an exemplary embodiment of a physical server
linked to one or more logical servers using virtualization software.
FIG. 4 is a block diagram of an exemplary embodiment of a physical server
linked to a logical server including logical and physical server agents
that facilitate management by the server cloud manager of FIG. 1.
FIGS. 5A, 5B and 5C are block diagrams illustrating respective steps of a
move procedure for moving a logical server from one physical server to
another.
FIG. 6 is a block diagram illustrating a replicating procedure for creating
a logical server on a physical server.
DETAILED DESCRIPTION OF EMBODIMENT(S) OF THE INVENTION
The following definitions are provided for this disclosure with the intent
of providing a common lexicon. A "physical" device is a material resource
such as a server, network switch, or disk drive. Even though physical
devices are discrete resources, they are not inherently unique. For
example, random access memory (RAM) devices and a central processing unit
(CPU) in a physical server may be interchangeable between like physical
devices. Also, network switches may be easily exchanged with minimal
impact. A "logical" device is a representation of a physical device to
make it unique and distinct from other physical devices. For example,
every network interface has a unique media access control (MAC) address. A
MAC address is the logical unique identifier of a physical network
interface card (NIC). A "traditional" device is a combined logical and
physical device in which the logical device provides the entire identity
of a physical device. For example, a physical NIC has its MAC address
permanently affixed so the physical device is inextricably tied to the
logical device.
A "virtualized" device breaks the traditional interdependence between
physical and logical devices. Virtualization allows logical devices to
exist as an abstraction without being directly tied to a specific physical
device. Simple virtualization can be achieved using logical names instead
of physical identifiers. For example, using an Internet URL instead of a
server's MAC address for network identification effectively virtualizes
the target server. Complex virtualization separates physical device
dependencies from the logical device. For example, a virtualized NIC could
have an assigned MAC address that exists independently of the physical
resources managing the NIC network traffic.
A "cloud" is a collection of logical devices. The essential element of a
cloud is that all logical devices in the cloud may be accessed without any
knowledge or with limited knowledge of the underlying physical devices
within the cloud. Fundamentally, a cloud has persistent logical resources,
but is non-deterministic in its use of physical resources. For example,
the Internet may be viewed as a cloud because two computers using logical
names can reliably communicate even though the physical network is
constantly changing. A "virtualized logical server cloud" as described
herein refers to a logical server cloud comprising multiple logical
servers, where each logical server is linked to one of a bank of physical
servers. The boundary of the logical server cloud is defined by the
physical resources controlled by a "cloud management infrastructure" or a
"server cloud manager" or SCM. The server cloud manager has the authority
to allocate physical resources to maintain the logical server cloud;
consequently, the logical server cloud does not exceed the scope of
physical resources under management control. Specifically, the physical
servers controlled by the SCM determine a logical server cloud's boundary.
"Agents" are resource managers that act under the direction of the SCM. An
agent's authority is limited in scope and it is typically task-specific.
For example, a physical server agent (PSA) is defined to have the
authority to allocate resources to logical servers, but does not have the
authority or capability to create administrative accounts on a logical
server. An agent generally works to service requests from the server cloud
manager and does not instigate actions on other agents.
FIG. 1 is an overview block diagram illustrating a virtualized logical
server cloud 101 implemented according to an embodiment of the present
invention including a server cloud manager 102. The virtualized logical
server cloud 101 is accessible to one or more remote terminals 105 via an
intermediate network system 103, such as the globally-accessible Internet,
although any type of network is contemplated. The virtualized logical
server cloud 101 includes one or more logical servers 106, individually
labeled LS 1, LS 2, . . . , LS N, where "N" is a positive integer
representing a total number of logical servers. The virtualized logical
server cloud 101 further includes a bank of physical servers 108, each
physical server individually labeled PS 1, PS 2, . . . , PS M, where "M"
is a positive integer representing a total number of physical servers, and
where M does not necessarily equal N and may be a smaller number. As
described further below, the bank of physical servers 108 establishes the
physical resources underlying the logical servers 106. In particular, each
logical server 106 is linked to and implemented on a corresponding one of
the physical servers 108. The virtualized logical server cloud 101
includes the SCM 102 that interfaces and controls each of the logical
servers 106 and the bank of physical servers 108. In the embodiment shown,
the SCM 102 includes a user interface (I/F) 104 that provides a web page
portal or other access mechanism to facilitate communication with the
remote terminals 105 via the network system 103. Each terminal 105 may be
located anywhere with access to the network system 103, and may be
configured with various levels of capability, including simple terminals,
thin client computers, low end PCs, etc. In this manner, a user of any
remote terminal 105 may login to and access any of the logical servers 106
of the virtualized logical server cloud 101 via the user interface 104 and
SCM 102 as though logging into a server directly or via a local area
network (LAN).
In one embodiment, a terminal 105 executes a keyboard/video/mouse (KVM)
client 107 that transmits keyboard and mouse commands to a selected
logical server 106 and that receives video and audio information from the
selected logical server 106. The SCM 102 provides KVM redirection either
by providing a KVM interface or by mapping the KVM client 107 to allow
direct KVM access to the selected logical server 106. In any event,
virtually all significant processing occurs at the logical server 106
rather than the terminal 105, although the terminal 105 may retain
substantial control of operation of the logical server 106 via the KVM
client 107. Also, the remote terminals 105 may include a standard (or
non-standard) browser, such as Netscape Navigator or Microsoft Explorer or
the like, that facilitates remote access. For example, a user employs the
local browser to access a web page associated with or implemented by the
user interface 104, where the web page enables the user to input user
credential information (e.g., username & password). The graphical user
interface (GUI) of the user interface 104 provides the mechanism (portal
or other interface) through which the user may access one or more logical
servers 106 based on permission. In one embodiment, the user interface 104
displays a stack of logical server graphics, each representing a
corresponding one of the logical servers 106 that the user has permission
to access. The user then interfaces the logical server graphics (e.g.
point and click) to login to or otherwise control a selected logical
server. It is noted that the user interface 104 web page may provide an
input to receive logical server information so that the user may directly
access a selected logical server if desired. The user interface 104 also
provides interfaces to provide SCM control of the physical server to
enable other functions including copy, move, start, shutdown, reset and
any other functions enabled by control over the physical server and
virtualization software.
The SCM 102 includes or is otherwise associated with a user database 110
that incorporates a mapping of users, the logical servers 106 and the
physical servers 108. In particular, the user database 110 incorporates
user credentials and the access information for one or more logical
servers 106 that the user has permission to access. Further, the user
database 110 incorporates the link information that maps each logical
server 106 with one of the physical servers 108. In this manner, each user
need only supply corresponding user credentials, and the SCM 102 accesses
and provides a corresponding list of the logical servers 106 for which the
user has permission to access. The user may select a logical server from
the list, such as by clicking a graphical icon or the like, and the user
may then login to or otherwise control the logical server. Alternatively,
the user may additionally supply information identifying a selected
logical server, and the SCM 102 provides access.
It is appreciated that the user dB 110 maintains the mapping to the
physical servers 108 and automatically accesses the appropriate physical
server corresponding to the selected logical server. In this manner, the
user does not have to supply physical server information and, in fact,
does not even need to be aware of any specific physical server access or
location information. Further, a logical server 106 may be transparently
moved from one physical server 108 to another without knowledge of or
participation by the user. As long as the user's logical server maintains
all of the attributes designated or desired by the user, the user need not
be concerned with the identity or location information of underlying
specific physical resources enabling operation of the logical servers 106.
FIG. 2 is a block diagram of an exemplary embodiment of the virtualized
logical server cloud 101 illustrating relationships between the logical
servers 106 forming a logical server cloud 201, the bank of physical
servers 108, a shared network 211 and the SCM 102. The bank of physical
servers 108 includes several individual physical servers individually
labeled PS A, PS B, PS C, etc. Each of the logical servers 106 is
non-deterministically linked to a corresponding physical server 108 as
illustrated by a corresponding links 205 (illustrated by dashed lines). As
shown, the logical servers LS 1-4 are linked to the PS A, the logical
servers LS 5-8 are linked to the PS B, and the logical servers LS 9-N are
linked to the PS C. It is appreciated that any desired number of physical
servers 108 may be included, and that each physical server may be linked
to any suitable number of logical servers 106.
It is noted that each logical server 106 is "deterministically" linked to a
specific physical server 108 at any given time, but that such linkage or
association is "non-deterministic" over time since the logical server may
be moved to another physical server. As described further below, each
logical server 106 may be moved to any other "compatible" physical server
108 of choice without destroying the identity of the moved logical server
106 as determined by its "persistent attributes". A compatible physical
server is one that provides the physical and logical resources needed to
retain the persistent attributes of the logical server 106 being moved. As
will be described further below, these resources include physical
resources such as CPU type, storage capacity, disk configuration, and
network connectivity. The resources also include logical resources such as
administrative control, cloud manager (SCM identity), software licenses,
processor capacity, and commercial/contractual restrictions. An example of
a software license as a logical constraint is a physical, CPU-based
database license. Software licenses are sometimes tied to physical servers
rather than logical servers, so that a logical server may "inherit"
licenses of the underlying physical server. Under this license model, the
logical server may be moved to another physical server if the new physical
server is licensed. Many software licenses follow this model including
most virtualization software. Nonetheless, software licenses may also be
constructed to follow logical servers since they may be tied to specific
licensed users.
Each physical server 108 includes a hardware layer 210, an operating system
(OS) layer 212 and a software layer 214. The hardware layer 210 forms a
portion of physical resources coupled to or otherwise interfaced with each
physical server. The hardware layer 210 includes a network resource "N"
217, a storage resource "S" 219, a KVM resource 221, a memory resource "M"
223 and a processor resource "P" 225. The term "resource" as used in this
context is intended to include one or more resources, such as, for
example, one or more NIC cards, one or more hard disk drives, multiple
input/output (I/O) resources, one or more memory devices, one or more
microprocessors, etc. The network resource 217 couples or otherwise
interfaces each physical server with the shared network 211, so that the
physical servers 108 may communicate with each other and to the SCM 102.
The network resource 217 may include, for example, one or more NICs or the
like that enable communications between each physical server and the
network 211. The shared network 211 may be implemented as a single network
fabric or may be segmented into multiple network fabrics. Multiple network
fabrics are desired to ensure scalability and security. The network 211
provides a communication link (not shown) to the intermediate network
system 103. For example, the network 211 may include a firewall or the
like associated with a particular network fabric, which provides an
interface to the network system 103.
Each physical server 108 includes a storage resource 219 that may include
one or more local disk drives, such as magnetic hard disk drives or the
like, for static or permanent storage of software, programs, data, etc.
The term "storage" as used herein also incorporates other media types
including removable media such as CD-ROM, Zip disks, floppy disks, or the
like. The storage resource 219 may also include communication links to one
or more shared storage resources 213 either separately or via the shared
network 211. The storage resources 213, 219 may each comprise a single
device (e.g. System Area Network (SAN)) or may be divided into multiple
physical and logical devices (e.g., File Transfer Protocol (FTP) and
Network Attached Storage (NAS) or the like). The storage resources 213,
219 may be implemented as a Redundant Array of Independent (or
Inexpensive) Disks (RAID) or the like with redundant information to ensure
data integrity. The storage resource 219 is preferably configured to use
multiple devices to ensure scalability. It is noted that network and
storage resources may be shared between the physical servers 108 using an
Ethernet or Fiber switching fabric. Access to the network and storage
resources is preferably logical rather than physical so that they act like
resource clouds.
Each physical server 108 also includes a keyboard, video and mouse (KVM)
resource 221 for interfacing corresponding general input/output (I/O)
devices, such as a keyboard, a video monitor, speakers and a mouse. The
KVM resource 221 includes, for example, keyboard, video, speaker and mouse
interface hardware and software drivers for coupling to each physical
server 108. Each physical server 108 includes a memory resource 223, such
as any combination of read-only memory (ROM) and random access memory
(RAM) devices or the like. Each physical server 108 includes a processor
resource 225, such as a central processing unit (CPU) including one or
more microprocessors or the like.
Each physical server 108 includes an operating system (OS) 227 within its
OS layer 212, such as any suitable standard OS offered by Microsoft,
including Microsoft Windows 98, 2000, etc. or Microsoft NT, or other
suitable operating systems such as those based on UNIX or Linux. The
present invention is not limited to any type of OS employed by the
physical servers 108 and each physical server may executed a different OS
independent of the other physical servers. Each physical server 108
executes virtualization software 229, within its software layer 214, where
the virtualization software 229 manages physical resources of the logical
servers 106 linked thereto. The virtualization software 229 facilitates
eliminating dependency between physical hardware and the logical
configuration of the logical servers 106. Virtualization software enables
separation of logical from physical resources. Such separation may be
achieved by controlled partitioning of the operating system or the
physical resources or by emulation of the operating system or emulation of
hardware. In one embodiment, the virtualization software 229 is merged
with or otherwise incorporates the OS 227. A separate logical server
interface may be provided to interface virtualization software that is
merged with the OS.
The SCM 102 is shown as a separate entity interfaced to the shared network
211 and the physical servers 108. The SCM 102, however, may be implemented
in any one of several different manners. In one embodiment, the SCM 102 is
implemented on a separate physical server or administrator computer,
similar to the physical servers 108, which is coupled via the network 211
and the shared storage resource 213 in similar manner as the physical
servers 108. In an alternative embodiment, the SCM 102 is a separate
logical server, similar to the logical servers 106, that is
deterministically or non-deterministically linked to any of the physical
servers 108. The SCM 102 may alternatively be implemented as a separate
application executing on any one of the logical servers 106. In yet
another embodiment, the SCM 102 is a distributed function comprising a
peer to peer application or the like. In any of these configurations, the
SCM 102 includes SCM software to manage the logical servers 106 and the
physical servers 108.
FIG. 3 is a block diagram of an exemplary embodiment of a physical server
108, such as the PS A, linked to one or more logical servers 106, such as
the logical servers LS 1-4. Although the physical server PS A includes the
hardware, OS and software layers previously described, only the
virtualization software 229 is shown for clarity. Each logical server 106
also includes a "hardware" layer 324, an OS layer 325 for executing an LS
operating system 326 and a software layer 327 for executing desired
software applications. Each LS OS 326 may be any desired OS as previously
described, such as those from Microsoft or based on UNIX, Linux, etc.
Also, each LS OS 326 is executed independently from every other LS OS 326,
or otherwise gives every appearance of independent operation from the
user's perspective. In the hardware layer 324, the logical server 106
includes a network resource 301, a storage resource 303, a KVM resource
305, a memory resource 307 and a processor resource 309 in a similar
manner as the hardware layer 210 of the physical server 108, and where the
term "resource" is used in a similar context. Each logical server 106 also
includes a host link "HL" 311 to a corresponding physical server 108 to
enable communication between the logical and physical servers.
The hardware layer 324 of each of the logical servers 106, however, does
not necessarily include actual hardware but instead provides virtualized
resources corresponding to the physical resources of or otherwise coupled
to the underlying physical server. As illustrated by links 313, the
network resource 301 of every logical server 106 is virtualized to the
corresponding network resource 217 of the underlying physical server. It
is noted that the network resource 301 of each logical server 106 is
independently virtualized to the network resource 217 to retain virtual
independence among the logical servers 106. In a similar manner, links 315
illustrate that the storage resource 303 of every logical server 106 is
virtualized to the corresponding storage resource 219 of the underlying
physical server. Also, links 317 illustrate that the memory resource 307
of each logical server 106 is virtualized to the corresponding memory
resource 223 of the underlying physical server. As illustrated by links
319, the processor resource 309 of every logical server 106 is virtualized
to the corresponding processor resource 225 of the un
