Patent Application
20060206699
This application claims the foreign priority benefit under Title 35, United States Code, § 119 (a)-(d), of Japanese Patent Application No. 2005-67553, filed on Mar. 10, 2005 in the Japan Patent Office, the disclosure of which is herein incorporated by reference in its entirety.
This invention relates to a network boot system.
A boot is a series of processes carried out first in a computer when the computer is switched on, to place a variety of software such as applications and utilities into an operable condition, and mainly consists of a startup sequence for an operating system (OS). A master boot record (MBR) allocated at the first sector of a storage device equipped in the computer provides a pointer indicating the location (storage area) in which the OS is stored, so that the computer locates the OS using the pointer and loads it from the storage area into memory. In general, the location of the OS indicated by the MBR is in the storage area of the storage device (local disk) equipped in the computer to be booted up.
On the other hand, the progress of network technology has enabled another implementation scheme in which an OS is loaded via a network from a computer other than the computer to be booted up, using a network boot program (NBP) or the like, as described in JP 2000-259583 A, the disclosure of which is herein incorporated by reference in its entirety. The boot implemented according to this scheme will be hereinafter referred to as a network boot. The applicant of the present application previously proposed a data storage/readout control for a mass storage server for enabling a computer to perform a network boot; for details, see JP 2004-287477 A, the disclosure of which is herein incorporated by reference in its entirety. This serves to bring the readout speed under control, which would otherwise decrease upon concurrent or congested access from many clients.
The network boot involves communication or transmission of OS data between the computer to be booted up and the computer storing the OS data. Communications protocols used for such OS data transmission may include, for example, the Internet Small Computer Systems Interface (iSCSI), as described in the Internet Engineering Task Force (IETF), “iSCSI” retrieved on Feb. 13, 2004 through the Internet at http://www.ietf.org/internet-drafts/draft-ietf-ips-iscsi-20.txt.
The conventional network boot schemes as described above would disadvantageously place a heavy load on the computer to be booted up. To be more specific, for example, a central processing unit or CPU of the computer to be booted up may run an NBP to transport the OS data from the storage server of another computer on the network over TCP/IP (Transmission Control Protocol/Internet Protocol), such as the Internet, using the iSCSI protocol, and load the transported OS data into the main memory for processing. Consequently, the network boot has been successfully completed and the OS is up and running, so that a specific operating environment is established. It is thus understood that the NBP executes the majority of the processing, in this type of the conventional network boot scheme, which causes the computer to run at a lower execution speed, and software vendors to bear a higher development cost.
The processing on the iSCSI protocol and TCP/IP includes security and reliability enhancing functionality, which reduces the execution speed of the NBP accordingly. Moreover, the NBP that is to be executed prior to the OS bootstrap needs to implement the TCP/IP and iSCSI, which can be processed by drivers on the OS, and thus causes the software vendors to bear a higher development cost.
It would be desirable to realize a new network boot scheme with a lower load placed on the computer to be booted up, and the present invention has been made with consideration given to the above-described disadvantages in the conventional methods.
Illustrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any of the problems described above.
In one aspect of the present invention, a computer transmits a boot request to a gateway server, and the gateway server, upon receipt of the boot request from the computer, receives boot data stored in a storage server using an upper protocol for security-enhanced communications, and transmits the boot data to the computer using a lower protocol for speed-oriented communications. Upon receipt of the boot data from the gateway server, the computer boots up using the received boot data.
The gateway server receives the boot data using the upper protocol and thus takes on the task of security and reliability enhancing functionality as a proxy for the computer to be booted up. Therefore, an inventive network boot scheme with a lower load placed on the computer to be booted up is realized.
The above aspect, further features and other advantages of the present invention will become more apparent by describing in detail illustrative, non-limiting embodiments thereof with reference to the accompanying drawings, in which:
A computer system as exemplary embodiments of the present invention will be described in detail with reference to the drawings. Referring now to
As shown in
The components (management server 4, computer 1, gateway server 2 and storage server 3) making up the computer system may be provided each as a specifically configured computer, which includes but not limited to a processor (or arithmetic unit) and a memory (or main memory). The processor is typically composed of a central processing unit (CPU), and the memory is typically composed of a random access memory (RAM). The processor loads a program into memory and interprets instructions given by the program and executes arithmetic operations according to the instructions for a variety of functionality.
Since the storage server 3 contains boot data (e.g., OS data) for booting up the computer 1 having no boot data in its local disk, access to the storage server 3 via the network 6 (outside the secure network 5) using secure protocol such as iSCSI is enabled in the gateway server 2 so as for the computer 1 to receive via the gateway server 2 the boot data stored in the storage server 3. Assuming that the computer system is installed in a typical office environment, employees' starting times are likely to come within a short period of time in the morning, and many computers 1 are booted up in that short period of time. When multiple computers 1 are booted up substantially in unison, access of excessively many computers 1 to the storage server 3 would take place, leading to serious congestions. In view of the circumstances, according to the present embodiment, the gateway server 2 is provided for relaying and controlling the communications between the plurality of computers 1 and the storage server 3, so that congested access of multiple computers 1 are controlled appropriately.
As shown in
On the other hand, the storage server 3 is included in an IP site 42, different in IP segment from the IP site 41. The IP site 42 makes up the network 6 (shown in
Turning to
The storage server 3 includes an OS storage unit 20 for storing an operating system or OS 16 that is to be used for network booting of the computer 1. The management server 4 includes an NBP storage unit 12 for storing a network boot program or NBP 13. The NBP 13 transfers OS data to the computer 1 from the storage server 3 that uses iSCSI protocol for communication, to start the OS 16, and thereby realizes network boot functionality of the computer 1. The management server 4 also serves as a DHCP (Dynamic Host Configuration Protocol) server and a TFTP (Trivial File Transfer Protocol) server (neither shown) according to one embodiment of the present invention.
To realize the network boot functionality, the computer 1 includes an NBP loader 10 for loading the NBP 13 into memory (of computer 1), an OS loader 14 for loading the OS 16, and a disk access handler 15 for handling a file system on a remote computer as if it were on a local disk. The NBP 13 according to the present embodiment does not have to provide functionality of enabling communications using TCP/IP or iSCSI protocol for enhancing security and reliability thereof. This allows each client computer 1 to be provided in a simplified construction at a low cost, without lowering the processing speed thereof.
The gateway server 2 includes a relay processing unit 17, a lower protocol processing unit 18, and an upper protocol processing unit 19. The relay processing unit 17 provides a data caching capability and a congestion control functionality to adequately respond to an upsurge or congestion of multiple boot requests. The lower protocol processing unit 18 serves to process data communication using a lower protocol to achieve high-speed communications, such as user datagram protocol or UDP. The upper protocol processing unit 19 serves to process data communications using an upper protocol to achieve security and reliability enhanced communications, such as TCP/IP and iSCSI protocol.
The gateway server 2 according to one embodiment of the present invention, as shown in
The program memory 102 stores application programs for causing the gateway server 2 to execute a predetermined set of processes for implementing the functions of relay processing unit 17, lower protocol processing unit 18, upper protocol processing unit 19, etc.
The input/output buffer 103 provides a memory area for buffering the data packets, and includes a receiving packet buffer 110 for temporarily storing request packets received and a transmitting packet buffer 111 for temporarily storing response packets to be transmitted, both of which are stored in a correlated manner and associated with a sender address 112 that is an IP address of each computer 1 originating the corresponding request packet, as shown in
The computer management table 104, as shown in
The cache table 105, as shown in
Communications via the network 5 are established using the lower protocol, such as UDP, and the lower protocol processing units 11 and 18 of the computer 1 and the gateway server 2 respectively handles data packets having a specific format conforming to the predetermined lower protocol. Each packet the lower protocol processing unit 18 (and 11) processes, as shown in
The general arrangement of the computer system according to one embodiment of the present invention has been described above. The next description will be directed to an operation of the computer system according to the present embodiment with reference made mainly to
A process of transmitting OS data and a process after transmitting the OS data in the computer system according to one embodiment of the present invention are illustrated in
As shown in
As described above, the data transport from the storage server 3 outside the secure network using iSCSI protocol over TCP/IP, which was executed by the NBP in the conventional network boot scheme, is executed by the gateway server 2 that can utilize the functions of operating system and drivers. Consequently, the execution speed of the NBP can be improved, and the development cost of the whole system can be reduced.
As shown in
Referring now to
First, the process of transmitting OS data (S180-S191) is described. The NBP loader 10 makes a request to the management server 4 for boot information of the computer 1 (S180). In cases where the management server 4 serves as a DHCP server and as a TFTP server storing the NBP 13, the boot information may include for example an IP address of the computer 1, an IP address of the management server 4 from which the NBP 13 is obtained, and a file name of the NBP 13.
Next, the management server 4 responds to the request and transmits the boot information of the computer 1 to the NBP loader 10 of the computer 1 (S181). The NBP loader 10 then makes a request to the management server 4 for the NBP 13 (S182). In response, the management server 4 allows the NBP 13 to be loaded into the computer 1 (S183).
The NBP loader 10 then gives the OS loader 14 instructions to start up (S184). To be more specific, the internal interface 106 through which the computer 1 accesses a disk is switched to the disk access handler 15. In actuality, it is realized by hooking the BIOS call. The OS loader 14 can load the OS 16 by following specified procedural steps. More specifically, to load the OS 16, data located at a specific position (at sector “0”) on a disk image for computer 1 in the storage server 3 is stored at a specific address in the computer 1, and executed.
The OS loader 14 that has thus received the instructions makes a request through the internal interface 106 to the disk access handler 15 for disk access to obtain the OS (S185). Then, the disk access handler 15 makes a request using the lower protocol to the gateway server 2 for disk access to obtain the OS (S186). The gateway server 2 in turn makes a request using the upper protocol to the storage server 3 for disk access to obtain the OS (S187).
In response to the request for disk access to obtain the OS, the process goes to the steps of transmitting the data 143 (see
Next the operation of the disk access handler 15 accessing the storage server 3 (S192-S197) is described. This operation is carried out for example when the OS 16 having finished its startup process utilizes the internal interface 106.
The OS 16 makes a request through the internal interface 106 to the disk access handler 15 for disk access (S192). The disk access handler 15 then makes a request using the lower protocol to the gateway server 2 for disk access (S193). The gateway server 2 in turn makes a request using the upper protocol to the storage server 3 for disk access (S194).
A process of responding to the request for disk access is described hereinafter. The storage server 3 transmits the data 143 to the gateway server 2 (S195). The gateway server 2 then transmits the data 143 to the disk access handler 15 (S196). The disk access handler 15 in turn transmits the data 143 to the OS 16 (S197).
The process after transmitting the OS data (S198-S199) is described. The OS 16 makes a request using the upper protocol to the storage server 3 for disk access (S198). The storage server 3 then transmits the data 143 to the OS 16 (S199). Likewise, once the OS 16 has started up, the OS 16 may directly access the storage server 3 using the upper protocol.
A description will be given of a process executed by the disk access handler 15 in the network boot process according to one embodiment of the present invention, with reference to
The disk access handler 15 makes a determination on waiting, i.e., determines whether the waiting period 144 of a packet is greater than “0”. If the packet is not placed in a queue of waiting (“No” at step S153), then the disk access handler 15 immediately responds to the request for disk access (S154), and the process returns to S150. On the other hand, if the packet is placed in a queue of waiting (“Yes” at step S153), then the disk access handler 15 waits for the waiting period 144 of the packet of data to be forwarded in response to the request, and the process goes back to S151.
A description will be given of a congestion control process of the network boot process executed in the computer system according to one exemplified embodiment of the present invention with reference to
The following are specific process steps of the algorithm shown in
Step 1: recording a sector number of data requested upon boot;
Step 2: detecting power off of computer 1;
Step 3: reading in advance the data from location indicated by the sector number recorded in step 1, so that the computer 1 can obviate the need for conforming whether cached data have been updated when establishing direct communications with the storage server 3 without intervention of the gateway server 2 after completion of the OS boot process;
Step 4: forwarding prefetched data in a cache if any corresponding to the request for access of the computer 1, to the storage server 3; and
Step 5: keeping track of the number of computers 1 booted up and the number of caching errors, for “queuing” the requests from the computers 1 in the gateway server 2 when the numbers of requests for network boot from the computers 1 go beyond the capacity of performance of the gateway server 2 and the storage server 3.
Referring now to
Subsequently, the relay processing unit 17 determines whether a request for disk access has been received (S162). If no request has been received (“No” at S162), the process returns to S160. On the other hand, if the relay processing unit 17 determines that a request has been received (“Yes” at S162), then the relay processing unit 17 receives data requested (S163). Next, the relay processing unit 17 makes a cache determination (S164). The “cache determination” refers to a determination made as to whether a desired piece of data is stored in the cache.
If the cache determination at S164 turns out to be “Yes”, then the relay processing unit 17 obtains requested data by obtaining relevant data 143 from the cache table 105, and stores the obtained data in the input/output buffer 103 (S166). Hereupon, the cache use time 133 of the relevant data is updated by the present time. According to the above process, the data in a cache can be utilized as boot data without the need for checking the update of the boot data in the storage server 3.
On the other hand, if the cache determination at S164 turns out to be “No”, the relay processing unit 17 accesses the storage server 3 (S165). To be more specific, the relay processing unit 17 obtains the requested data from the storage server 3, and stores the obtained data in the input/output buffer 103 and in the cache with other pieces of information of the cache table 105. If the capacity of cache (memory) becomes short, the relay processing unit 17 discards one or more of the oldest data.
Next, the relay processing unit 17 carries out a congestion control process (S167) as illustrated in
Then, the relay processing unit 17 further updates the computer management table 104 (S168); namely, the relay processing unit 17 sets the present time if “0” is set in the startup time 123, “Power on” in the computer status 122, and “Off” in the waiting status 125. Next, the relay processing unit 17 transmits the obtained data to the computer 1 which has requested therefor (S169). If the waiting period 124 in the computer management table 104 is not “0”, the value of the waiting period 124 is set in the corresponding field in the data packet, i.e., the waiting period 144, “0” is set in the waiting time 124, and “On” is set in the waiting status 125.
Operation of the computer system according to one embodiment of the present invention has been described above. Comparing with some examples, distinctive advantageous effects of embodiments of the present invention will be described with reference to
It is contemplated that various modifications and changes may be made to the exemplary embodiments of the invention without departing from the spirit and scope of the embodiments of the present invention.
For example, the number of each component of the computer system is not limited to that illustrated in
Each component constituting the computer system may be embodied separately in one unit enclosed in a single housing, one unit having functions of multiple units may be embodied in a single housing. For example, a computer system including n units of computers 1 and one unit of gateway server 2 may be reconfigured into another computer system including (n−1) units of computers 1 and one unit of gateway serer 2 doubling as computer 1 in functionality. Accordingly, even when each of the components of the computer system has levels of performance different from one another, functions conforming to their respective level of performance can be assigned to the respective components.
Further, the gateway server 2 according to one embodiment of the present invention as described above is configured to have the both functions of iSCSI processing and TCP/IP processing; however, the gateway server 2 may be configured to have one of these functions.
The network boot methods consistent with the present invention as described above may be embodied in the form of a computer program (computer program product) which may be stored in a variety of computer readable media for distribution or execution, and arranged independently in a specifically designed computer system or associated with various types of existing computer systems which is part of a network environment or on which a network system is implemented.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-067553 | Mar 2005 | JP | national |
