Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/969,329, filed Dec. 15, 2010, which application is incorporated herein by reference in its entirety. 
     U.S. patent application Ser. No. 12/969,329 is a non-provisional application that claims priority benefits under Title 35, United States Code, Section 119(a)-(d) from European (EP) Patent Application entitled “METHOD AND SYSTEM FOR HANDLING DATA TRANSFER IN A LAN-FREE ENVIRONMENT” by Alain Lentini and Jarl Theuwissen, having Patent Application No. EP09306262.8, filed on Dec. 18, 2009, which EP Patent Application is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     The disclosure relates to data processing, and more particularly to the handling of data transfer in a LAN-free environment. 
     2. Background 
     Backup and restore operations pose various issues. In particular, backup on storage tape drives pose specific issues. For example, a same number of backup cards and of partitions may be required. Some existing approaches to solve these issues use particular communications systems between servers of the architecture, other approaches mutualize resources, and still other approaches leverage virtualization mechanisms. 
     US Patent application 20080091896 entitled “Storage system and data management method” for example discloses a storage system and a data management method which can reduce the load on a virtualization apparatus by executing backup processing or restoration processing within one apparatus in which an externally connected storage apparatus and a tape library apparatus are installed. The storage system includes a virtualization apparatus and an external storage apparatus, wherein the virtualization apparatus comprises an actual volume for storing data sent from a host apparatus, formed in a storage area provided by a physical disk. The virtualization apparatus further comprises a virtual volume paired with the actual volume, for storing replicated data for the data. The external storage apparatus comprises a logical volume that functions as an actual storage area for the virtual volume and a tape associated with the logical volume, for storing the replicated data, wherein the external storage apparatus has a copy unit for copying the replicated data stored in the logical volume to the tape. Whereas this approach leverages a virtualization mechanism, it still presents drawbacks. 
     During backup and restore operations, the use of the Local Area Network (LAN) may also be highly solicited, leading to a negative impact on the network traffic for existing and active users. For this reason, “LAN-free” backups are increasingly operated. A LAN-free backup is a backup of the data of a server to a shared central storage device without sending the data over the local area network (LAN). 
     There is a need for a system and method of efficiently managing backup or restore operations and in particular efficient handling of data transfer in a LAN-free environment. 
     SUMMARY OF THE PREFERRED EMBODIMENTS 
     In order to address these and other problems, embodiments for handling LAN-free data transfer are provided. 
     Certain embodiments relate to the usage of tape drives by virtual environments, and more particularly to the efficient connection of a tape drive from a storage area network to a logical partition by using a Virtual LAN provided by a virtual environment. 
     Certain embodiments provide for the sharing Storage Area Network tape drives using host bus adapter cards with several logical partitions. 
     Certain embodiments avoid the reconfiguration of Storage Area Network tape drives in the Operating System when the logical partition moves to a new hardware. 
     An advantage of certain embodiments relate to the sharing of Fibre Channel (FC) technology in the context of LAN-free backup. 
     An additional advantage of certain embodiments is thus to share resources between several servers. 
     Yet another advantage is to virtualize a Fibre Channel card between several servers. 
     Further advantages of certain embodiments will become clear to the skilled person upon examination of the drawings and detailed description. It is intended that any additional advantages be incorporated therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of certain aspects of the invention will now be described with reference to the following drawings, in which: 
         FIG. 1  shows a LAN-free server architecture design for an embodiment of the present invention; 
         FIG. 2  shows the live Partition Mobility design with LAN-free server; 
         FIG. 3  shows the workflow of the data transfer during a backup or a restore of the data; 
         FIG. 4  shows the workflow of the backup/restore protocol information transfer during a backup or a restore of the data; 
         FIG. 5  shows a workflow of a live Partition Mobility operation. 
     
    
    
     To facilitate description, any numeral identifying an element in one figure will represent the same element in any other figure. 
     DETAILED DESCRIPTION 
     The following text presents embodiments in the context of LAN-free backup or restore but it is to be understood that it is not limited to this specific backup or restore context. In particular, the figures and the description discuss a preferred embodiment with the use of IBM pSeries® servers. Further embodiments of the invention are not restricted to these proprietary environments or products, which are provided for exemplary purposes only. 
     A LAN-free backup is a backup of data from a server to a shared and central storage device. The goal of a LAN-free backup is to reduce the load on LAN and reduce the time required to complete the backup. 
     Therefore, such a LAN-free backup process often uses a Storage Area Network (SAN). This type of backup offers an alternative way to backup data: this is no more a simple data copy to network-attached storage (NAS) over LAN. There may exist a central backup server arbitrating access to devices (for all the other SAN servers), which does not however handle data stream itself. Without such a backup server, the storage facility (usually a virtual tape library, or VTL) is adapted to handle multiple data accesses without intermediate components. 
     Fibre Channel (FC), is a gigabit-speed network technology primarily used for storage networking. FC ensures the connection between a computing device and the associated storage device. Fibre Channel is standardized: the ANSI working group X3T11 defines the Fibre Channel specifications. It has become the standard connection type for Storage Area Networks (SAN) in enterprise storage. Fibre Channel signaling can run on both twisted pair copper wire and fibre-optic cables. The Fibre Channel Protocol (FCP) is a transport protocol which predominantly transports SCSI commands over Fibre Channel networks. 
       FIG. 1  shows the LAN-free server architecture design.  FIG. 1  comprises a logical partition which hosts a LAN-free backup client  100 , a LAN-free client virtual Ethernet adapter dedicated to the data backup  101 , a virtual Ethernet adapter LAN connectivity  102 , a IBM pSeries® physical server  103 , a Logical partition  120  that hosts a LAN-free server, a LAN-free server virtual Ethernet adapter  120  dedicated to data backup, LAN-SAN APIs  121  and  122  (the Storage Agent handles the communication with the backup server  140  over the LAN but sends the data directly to SAN attached tape library  160 ), a Virtual Input Output partition  130 , a Virtual Ethernet server adapter  131  which is the interface between virtual Ethernet clients and physical Ethernet LAN, a backup server  140 , an Ethernet network adapter  141 , a tape library  160 , a Virtual LAN  180  dedicated to the data backup, a Virtual LAN  181  dedicated for the network communication, physical interfaces  184  connected to the storage area network to send data to the library, the Local Area Network (LAN)  187 , a backup server connection  189  to the Local Area Network (LAN), a tape library connection to the Storage Area Network (SAN)  190  and a Storage Area Network (SAN)  192 . 
     In a typical design of a virtualized architecture, the physical server (IBM pSeries® for example) hosts several partitions  100  with operating systems used for production applications. These operating systems share the same physical resources owned by a specific partition. In  FIG. 1  this specific partition is named VIO server  130 . In this architecture, the shared resources are used for LAN and SAN data communication. Virtualized structures to the interface between client partitions and the physical interfaces hosted by the VIO partition  130  are required. 
       FIG. 1  shows the virtualized elements used for network LAN data exchange: the Virtual Ethernet server adapter  131  is the interface between virtual Ethernet clients and physical Ethernet LAN  187 . For the production data access used by the client partitions  100 , there may be used fibre channel cards owned by the VIO partition  130  and shared between all the client partitions. These virtualizations provide a hardware sharing for LAN and SAN disks access to client partitions. 
     Certain embodiments of the invention provide a similar virtualization, but specifically for SAN tape sharing between client partitions  100 . The virtualization consists in sharing fibre channel hardware cards  184  connected to the SAN which is connected to the tape library. The advantage is thus to use few fibre channel hardware cards and share them instead of installing one or more fibre channel hardware cards on each client partition. 
     In  FIG. 1 , the LAN-free server partition can be any of the client partition of the IBM pSeries® server. 
     In operation, in a first step data is transferred from the client partition  100  to the LAN-free server partition  120  that owns the fibre channel cards and shares them with all client partitions. In certain embodiments, this step is operated using a virtual Ethernet LAN  180  provided by the IBM pSeries® server  103  for example. A virtual LAN, commonly known as a vLAN, has the same attributes as a physical LAN, but defines a logical grouping of networking devices. Network reconfiguration can be operated through software (instead of physically relocating devices). Alternatively to a vLAN, it may be a physical LAN but according to an embodiment, there is a sharing of hardware material instead of assignments of such material to particular tasks. 
     A second step is the conversion of data coming from virtual LAN  180  to send it to the SAN fibre channel cards  184  to go then to the tape library  160 . This conversion is done by a tool currently named “API LAN-SAN”  122 . In IBM environments, this API is named “LAN-free storage agent”. The API LAN-SAN enables the conversion from TCP (in the TCP/IP stack) into the FC protocol acting as a “gateway”. When data are received by the tape library  160 , they are written on a set of tapes managed by the tape library. This mechanism can be initiated by a backup of the data owned by one of the client partitions  100  or by a restore of the data of one of client partitions  100 . In case of a data backup, pieces of data come from the client partition  100  toward the tape library  160 , and in case of a data restore, pieces of data come from the tape library  160  toward one of the client partitions  100 . 
     A backup or a restore of the client data is initiated and managed by one of the backup server  140 . To manage this backup or restore operation, the backup server communicates with the client partition. It uses therefore a physical LAN network  187 . As the LAN hardware cards are virtualized on the IBM pSeries® server models  103 , they are hosted by the VIO partition which shares them between available client partitions  100  via a virtual LAN  181  provided by the IBM pSeries® server  103 . A virtual structure, the virtual Ethernet server adapter  131  is used to generate the interface between physical and virtual LAN. During backup or restore operations, the backup server exchanges backup protocol information with the client partition. 
       FIG. 2  shows the Live Partition Mobility (LPM) design with LAN-free server.  FIG. 2  comprises: a logical partition that hosts a LAN-free backup client  200 ; a Logical partition that hosts a LAN-free server on the server A  210 ; a Tape library  220 ; a Logical partition that hosts a LAN-free server on the server B  230 ; a Physical server A  240 ; a Physical server B  250 ; backup dedicated VLAN used for data transfer  261 ; a LAN-free client of IP address x.y.z.b, a virtual Ethernet adapter  262 ; a LAN-free server  263  of IP address x.y.z.3 (for example); a LAN-free client virtual Ethernet adapter  270  linked to the VIO; the Local Area Network (LAN)  271  used for control and protocol streamed by the backup server. 
     In case of live partition mobility (LPM), any client partition  100  can move online from its IBM pSeries® 240 to the other IBM pSeries® 250 dynamically. Certain embodiments include operations to perform the following: 
     (i) SAN Tape library access after live partition mobility 
     
         
         
           
             When the client partition  100  moves from the first IBM pSeries® 240 to the other IBM pSeries® 250, it can work with the LAN-free server partition  230  owned by the other IBM pSeries®. 
             As the same IP address is defined on the LAN-free server partition virtual Ethernet  263 , the client partition IP address  262  can still communicate with the tape library via the new LAN-free server partition  230 .
 
(ii) Data SAN disks client partition access after live partition mobility
 
             The data SAN disks access is not interrupted during live partition mobility. As each IBM pSeries® server is connected to the same SAN, the Live Partition Mobility (LPM) copies the virtual devices that manage the access to the SAN disks from the source IBM pSeries® VIO partition  130  to the destination IBM pSeries® VIO partition.
 
(iii) Physical LAN access from client partition after live partition mobility
 
             The physical Local Area Network (LAN)  271  used for control and protocol stream by the backup server  140  keeps connected during the Live Partition Mobility (LPM). As the virtual structures exist on the destination IBM pSeries® and are connected to the same VLANs on the physical switches, the Live Partition Mobility (LPM) connects the client partition  100  to the same VLANs after the move. This means that the same backup server can continue to control the backup or restore operations and the same tape library can also be used after the move.
 
(iv) LAN-free server partition access via virtual Ethernet LAN after Live Partition Mobility
 
             The dedicated VLAN  261  used for data transfer uses the same subnet and the IP address is common for all LAN-free servers  263  hosted by the two physical servers (shown in the drawing as physical server A  240  and as physical server B  250 ). 
             After the migration of the logical partition that hosts the LAN-free client  200  from physical server IBM pSeries® A  240  to the physical server IBM pSeries® B  250 , the LAN-free client  200  is directly linked to the common IP address of the LAN-free server  263 . This configuration avoids any network or devices reconfiguration. 
           
         
       
    
       FIG. 3  shows the workflow of the data transfer during a backup or a restore of the data.  FIG. 3  describes the process of the data transfer from the client partition  100  to the tape library  160  in case of a backup operation of the client data. In case of a restore operation, the process is similar but in the reverse direction. 
     At step  300 , the data backup operation (or restore) is started on the LAN-free client  100 . 
     At step  310 , the client sends data to LAN-SAN API via virtual Ethernet client adapter  101 . 
     At step  320 , the client Ethernet adapter transmits data through virtual LAN  180 . 
     At step  330 , the Virtual LAN transmits data to virtual Ethernet client adapter  121 . 
     At step  340 , the virtual Ethernet client adapter transmits data to LAN-free storage agent  122 . 
     At step  350 , the LAN-SAN API sends data to tape library via SAN physical interfaces  184 . 
     At step  360 , the SAN connection transmits data to tape library (SAN connection of Tape library  190 ). 
     At step  370 , the data is written on tape library  160  until the end of the backup. 
     At step  380 , if the data backup is not finished, the process returns to step  310 . 
       FIG. 4  shows the workflow of the backup/restore protocol information transfer during a backup or a restore of the data. The workflow shown on  FIG. 4  describes the process of backup protocol information exchange between the client partition  100  and the backup server  140  to manage the backup or restore of the data of the client partition  100 . 
     At step  400 , the data backup (or restore) is started on the LAN-free client  100 . 
     At step  410 , the client exchanges Protocol Information with backup server via virtual Ethernet client adapter  102 . 
     At step  420 , the virtual Ethernet client adapter transmits or receives Protocol Information through the virtual LAN  181 . 
     At step  430 , the virtual LAN transmits/receives Protocol Information to/from VIO server  130 . 
     At step  440 , the VIO server transmits/receives Protocol Information to/from virtual Ethernet server adapter  131 . 
     At step  450 , the virtual Ethernet server adapter transmits/receives Protocol Information to/from Ethernet adapter  141  of the backup server  140 . 
     At step  460 , the Physical Ethernet adapter of the backup server transmits/receives Protocol Information to backup server  140 . 
       FIG. 5  shows a workflow of a live Partition Mobility operation. 
     The LAN-free client  200  sends the data of the backup through the dedicated VLAN  261  to the IP address dedicated to the LAN-free servers  263 . The LAN-free servers are hosted on different physical servers (in the figure, as physical server A  240  and physical server B  250 ). 
     LAN-free servers are attached by Storage Area Network SAN  271  to the Tape library. The LAN-free clients, LAN-free servers and backup server  221  are connected to a Local Area Network LAN  271  providing the control and protocol information. 
     Alterations and modifications may be made to the above without departing from the scope of the invention. Naturally, in order to satisfy local and specific requirements, a person skilled in the art may apply to the solution described above many modifications and alterations. Particularly, although the present invention has been described with a certain degree of particularity with reference to preferred embodiment(s) thereof, it should be understood that various omissions, substitutions and changes in the form and details as well as other embodiments are possible; moreover, it is expressly intended that specific elements and/or method steps described in connection with any disclosed embodiment of the invention may be incorporated in any other embodiment as a general matter of design choice. 
     For example, similar considerations apply if the computers have different structure or include equivalent units; in any case, it is possible to replace the computers with any code execution entity (such as a PDA, a mobile phone, and the like). 
     Similar considerations apply if the program (which may be used to implement each embodiment of the invention) is structured in a different way, or if additional modules or functions are provided; likewise, the memory structures may be of other types, or may be replaced with equivalent entities (not necessarily consisting of physical storage media). Moreover, the proposed solution lends itself to be implemented with an equivalent method (having similar or additional steps, even in a different order). In any case, the program may take any form suitable to be used by or in connection with any data processing system, such as external or resident software, firmware, or microcode (either in object code or in source code). Moreover, the program may be provided on any computer-usable medium; the medium can be any element suitable to contain, store, communicate, propagate, or transfer the program. Examples of such medium are fixed disks (where the program can be pre-loaded), removable disks, tapes, cards, wires, fibres, wireless connections, networks, broadcast waves, and the like; for example, the medium may be of the electronic, magnetic, optical, electromagnetic, infrared, or semiconductor type. 
     In any case, the solution according to the present invention lends itself to be carried out with a hardware structure (for example, integrated in a chip of semiconductor material), or with a combination of software and hardware. 
     Embodiments can thus take form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. Certain embodiments are implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. In a high performance system, a hardware implementation of the virtualization mechanism bundled with image generation processing may prove advantageous for example. 
     Furthermore, certain embodiments can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer-readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. 
     IBM pSeries® is a registered trademark of IBM Corporation

Technology Category: 5