Abstract:
A method for storing data by utilizing optical disks employs interleaving and sequential modes and a high watermark. The high watermark is a threshold value for an optical disk to a predefined portion of the total storage capacity, thereby insuring the existence of a spare capacity for each optical disk. A method combining the interleaving mode and the high watermark provides more efficient data storing and searching to the user, thereby reducing movement time of the optical disks and enabling many users to search for desired information on the optical disks in a more efficient manner.

Description:
CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for METHOD FOR STORING DATA BY UTILIZING THE OPTICAL DISKS earlier filed in the Korean Industrial Property Office on the 6th of February 1998 and there duly assigned Ser. No. 3445/1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention is related to a method for storing data by utilizing optical disks. More specifically, the present invention relates to a method for storing to a database information on the use of the optical disks and the optical disks themselves, and providing interleaving and sequential modes and a high watermark when storing the data by utilizing a plurality of optical disks in a juke box. 
     2. Related Art 
     Jukeboxes are utilized in a document imaging system, document managing system, or backup system. The jukeboxes can use a plurality of optical disks in order to store data of huge capacity. Both sides of the optical disks can be used to store the data. After a plurality of optical disks, comprising a logical volume, are inserted into optical disk drive(ODD), the data are stored, and subsequently the stored data are searched. 
     When many users request the jukebox to read the data stored on the opposite side of the present optical disk, the system must find the data storage side, and then frequently turn over and insert the optical disk. 
     When a specific optical disk is filled with data up to its available capacity, so that the optical disk has no more available capacity, storing additional data to the corresponding optical disk is impossible, and efficient management of the optical disk is impossible. 
     As a result of the latter problems, multiple disk systems have been developed. In such a system, when a first side of a two-sided disk is filled, further data is stored on the second side. Moreover, when both sides of a given disk are filled to capacity, a subsequent disk is selected for data storage on both sides thereof. 
     Inefficient disk management occurs when several users request data stored on different sides of different optical disks since turning over and insertion of different optical disks are required. 
     A prior art patent is U.S. Pat. No. 4,987,533 of Clark et al., which discloses a METHOD OF MANAGING DATA IN A DATA STORAGE HIERARCHY AND A DATA STORAGE HIERARCHY THEREFOR WITH REMOVAL OF THE LEAST RECENTLY MOUNTED MEDIUM to Clark et al. The method of this patent is different from the present invention, and is burdened by the disadvantages discussed herein. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method for storing data up to a dynamically allocated size of an optical disk by providing a high watermark which controls storage capacity in a software method, and for storing additional related information to the identical optical disk. 
     In one aspect of the invention, a method for storing data by utilizing a plurality of optical disks designated as a logical storage volume comprises the steps of: inputting a storing mode of the optical disk; finding the optical disk for which the storing mode is inputted; appointing the storing mode to the optical disk if the optical disk is found; storing the appointed storing mode information to the storage volume information database; searching the storing mode information from the storage volume information database when a request to store data to the corresponding optical disk is made; checking the remaining empty capacity of the corresponding optical disk according to the searched storing mode; and storing data when the checked optical disk has remaining capacity (i.e., vacant capacity). 
     An optional storing mode of the optical disk comprises the steps of: (a) storing data to the side A (or front side) of the optical disk; (b) storing data to the side B (or rear side) of the corresponding optical disk when the side A is filled with data; and (c) performing a sequential mode by searching the next optical disk in order to store data according to the steps (a) and (b), when the side B of the optical disk is filled. 
     Another optional storing mode of the optical disk comprises the steps of: (1) receiving a user request to store data on an optical disk in the storage volume; (2) finding the optical disk on which to store the requested data on side A thereof; (3) storing data to side A of the found optical disk; (4) finding the next optical disk on which to store the requested data on side A thereof when side A of the present optical disk is full; (5) finding an optical disk having capability of storing data to side B thereof when the plurality of the side A&#39;s of the installed optical disks are full; (6) storing data to side B of the found optical disk; (7) finding the next optical disk on which to store the requested data to side B thereof when side B of the current optical disk is full; (8) requesting the user to install additional optical disks when no more vacant optical disks are found; and (9) performing an interleaving mode repeating the steps (1) to (8) when optical disks are found. 
     In the step of checking for remaining empty capacity, a threshold value indicating storage restriction is defined as a high watermark, and the high watermark is applied to each optical disk. The values of the high watermark are inputted by the user for each optical disk, and are stored to the storage media information database. 
     A method of storing the values of the high watermark comprises the steps of: inputting by the user of the value of the high watermark for an optical disk; searching an appointed optical disk; setting the value of the high watermark for the optical disk to the inputted value of the high watermark when a searched optical disk exists; and storing the set high watermark information to the storage media information database. 
     A method for storing data by utilizing the high watermark comprises the steps of: requesting to store data to an optical disk; comparing the capacity predefined by the high watermark to the sum of the used capacity of the corresponding optical disk and the requested capacity; storing data to the corresponding optical disk and computing the used capacity when the sum of the used capacity of the corresponding optical disk and the requested capacity is less than the capacity predefined by the high watermark; determining whether to append the data to an identical document when the sum of the used capacity of the corresponding optical disk and the requested capacity is not less than the capacity predefined by the high watermark; storing data to another available optical disk when not appending data to the identical document as a result of the previous determining step; comparing the sum of the used capacity of the optical disk and the requested capacity to the available capacity of the optical disk when appending data to an identical document as a result of the previous determining step; storing data to another available optical disk when the sum of the used capacity of the optical disk and the requested capacity is not less than the available capacity of the optical disk; and modifying the high watermark with the sum of the used capacity and the requested capacity and storing data to the optical disk when the sum of the used capacity of the optical disk and the requested capacity is not less than the available capacity of the optical disk. 
     In another aspect of the present invention, a method for storing data by utilizing a plurality of the optical disks designated as a logical storage volume comprises the steps of: (1) receiving a user request to store data to an optical disk in the storage volume; (2) finding an optical disk on which to store the requested data on side A thereof; (3) storing data to side A of the found optical disk; (4) finding a next optical disk on which to store the requested data on side A of thereof when side A of the current optical disk is full; (5) finding an optical disk having the capability of storing data on side B thereof when the plurality of the side A&#39;s of the installed optical disks are full; (6) storing data on side B of the found optical disk; (7) finding a next optical disk on which to store the requested data on side B thereof when side B of the current optical disk is full; (8) requesting the user to install additional optical disks when no more optical disks are found; and (9) repeating the steps (1) to (8) when optical disks are found. 
     In another aspect of the present invention, a method for storing data by utilizing the optical disks applies a high watermark to each optical disk in order to determine the volume available to store data, the high watermark being defined as a threshold value which designates a data storage restriction, and a plurality of the optical disks being designated as a logical volume. 
     A method to store the high watermark comprises the steps of: inputting by a user of a value of the high watermark for an optical disk; searching a designated optical disk; setting a value of the high watermark for the optical disk as the inputted value of the high watermark when a searched optical disk exists; and storing the set high watermark information to a storage media information database. 
     A method for storing data by utilizing the high watermark comprises the steps of: requesting to store data to the optical disk; comparing a capacity predefined by the high watermark to the sum of the used capacity of the corresponding optical disk and the requested capacity; storing data to the corresponding optical disk and computing the used capacity when the sum of the used capacity of the corresponding optical disk and the requested capacity is less than the capacity predefined by the high watermark; determining whether to append data to an identical document when the sum of the used capacity of the corresponding optical disk and the requested capacity is not less than the capacity predefined by the high watermark; storing the data to another available optical disk when not appending data to an identical document as a result of the previous determining step; comparing the sum of the used capacity of the optical disk and the requested capacity to the available capacity of the optical disk when appending data to an identical document as a result of the previous determining step; storing data to another available optical disk when the sum of the used capacity of the optical disk and the requested capacity is not less than the available capacity of the optical disk; and modifying the high watermark with the sum of the used capacity and the requested capacity, and storing data to the optical disk when the sum of the used capacity of the optical disk and the requested capacity is not less than the available capacity of the optical disk. 
     The high watermark for each optical disk is stored by the user to a storage media information database. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
     FIGS. 1A and 1B illustrate a method for utilizing optical disks; 
     FIG. 2 illustrates a schematic diagram for storing data by utilizing optical disks according to the present invention; 
     FIG. 3 illustrates a flow chart for assigning a storing mode of the optical disks according to the present invention; 
     FIG. 4 illustrates a flow chart for storing data by an interleaving mode according to the present invention; 
     FIG. 5 illustrates a flow chart for assigning a high watermark to an optical disk according to the present invention; and 
     FIG. 6 illustrates a flow chart for storing data by utilizing a high watermark for an optical disk according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides a storing method by means of an interleaving mode in combination with a sequential mode when storing data to a logical volume comprising a plurality of optical disks. In the interleaving mode, after all side A&#39;s of optical disks are used, the side B&#39;s of the optical disks are used. Through the above procedure, a plurality of users can concurrently utilize the optical disks. 
     When storing data to a side of an optical disk, a high watermark for controlling the storage capacity in a software method is utilized. Through this procedure, the optical disk is not fully used and, when appending data relating to stored information, the related information may be stored in an identical optical disk. 
     FIGS. 1A and 1B illustrate a method for utilizing optical disks. As illustrated, three optical disks comprising a logical volume are inserted into the ODD in due course so as to store the data. More specifically, FIGS. 1A and 1B show a method for storing the data to the optical disk by utilizing the sequential method. As seen in FIG. 1A, an optical disk has two sides, A and B. If each side of the optical disks is assumed to contain sufficient volume to store the data, then data is stored to the side  11  of the optical disk  1 . When the side  11  is full, data is stored to the side  12  of the optical disk  1  (step 1). When the side  12  is full, data is stored to the side  13  of the optical disk  2  (step 2). When the side  13  is full, data is stored to the side  14  of the optical disk  2  (step 3). When the side  14  is full, data is stored to the side  15  of the optical disk  3  (step 4). Finally, when the side  15  is full, data is stored to the side  16  of the optical disk  3  (step 5). 
     Thus, when data is fully stored to a side A or side B up to its available capacity, if a user tries to store additional data related to the existing stored data to the identical side, he cannot store the data to the corresponding side of the optical disk. Therefore, the data must be stored to another side of the same optical disk or to another optical disk. Subsequently, when the user tries to search for the related information, he has to search many optical disks or stored sides, thereby increasing the search time. 
     In a jukebox system with a plurality of optical disks, when the data is stored to the optical disks sequentially, optical disk by optical disk, then when many users request data which are stored to the different sides of the optical disks, the jukebox sometimes has to turn over and insert the optical disks to search for the desired information. 
     Also, when a user tries to store additional data to an optical disk already filled to its available capacity, the data is stored to another side or to another optical disk because the data cannot be stored to the side of the optical disk containing the related information. Accordingly, the probability of changing optical disks increases, thereby preventing efficient management of the optical disks. 
     FIG. 2 illustrates a method for storing data by utilizing optical disks according to the present invention. A plurality of optical disks may be utilized but, for convenience of explanation, the number of the optical disks is set to three. Thus, an arrangement of optical disks  1 ,  2  and  3  having sides  11 ,  12 ,  13 ,  14 ,  15  and  16  (similar to FIG. 1B) are shown in FIG.  2 . 
     As illustrated, in a logical volume comprising the three optical disks, a side on which to store data is assigned by utilizing an interleaving mode. The side A&#39;s are assigned and, through steps  21  and  22 , the data is stored to the side A&#39;s. When all side A&#39;s are used, then the side B&#39;s are assigned and, through steps  23 ,  24 , and  25 , the data is stored to the side B&#39;s. 
     FIG. 3 illustrates a method for assigning a storing volume and a corresponding storing mode of the optical disks according to the present invention. The storing mode (sequential or interleaving) is requested in step s 301 . A volume for storing the data is found in step s 302 . If the volume is found, the information (sequential or interleaving) relating to the storing mode is assigned in step s 303 , and the information is stored to the storage volume information database by a request for modifying the database information in step s 304 . If the volume is not found, the process is terminated in step s 305 . 
     After the storing mode is assigned, when the request to store data to the storage volume occurs, an optical disk is selected according to the assigned storing mode and the data is stored by the sequential or interleaving mode. 
     FIG. 4 illustrates a method for storing the data by the interleaving mode according to the present invention. 
     If the request to store data to an optical disk having available storage capacity occurs in step s 401 , the storage mode (sequential or interleaving) is checked in step s 402 . If not utilizing the interleaving mode, the data is stored to the optical disk by utilizing the sequential mode in step s 407 . If utilizing the interleaving mode, the optical disk available for side A is found in step s 403 . If the optical disk available for side A exists, the corresponding optical disk is selected and the data is stored in step s 404 . 
     When all the optical disks available for side A are filled with data, the optical disks available for side B are found in step s 405 . If the optical disks available for side B are found, the found optical disks are selected and the data is stored in step s 406 . But, if the optical disks available for side B are not found, an additional optical disk is requested in step s 408 . 
     When utilizing the above mode, the user can easily use and modify the information on the storage modes because a capability of displaying the information on the storage mode of the present storage volume can be provided. 
     In the procedure of finding available optical disks, a determination must be made as to whether or not the side of the found optical disk has additional storage capacity. In this case, the high watermark function is adopted. The high watermark is a threshold value indicating the capacity to store data on each optical disk. For example, if the high watermark is set at 90%, then an optical disk with the high watermark of 90% stores data up to 90% of its capacity, and 10% of the capacity remains as a spare capacity. 
     FIG. 5 illustrates a method for assigning a high watermark to a specified optical disk according to the present invention. 
     If a high watermark of an optical disk for storing the data is inputted in step s 501 , the specified optical disk is found in step s 502 . If the specified optical disk is not found, the process is terminated (since the corresponding optical disk does not exist) in step s 505 . If the specified optical disk is found, the inputted high watermark is set as the high watermark of the corresponding optical disk in step s 503 . The information on this function is stored to the storage media information database by a request to modify the database information in step s 504 . 
     When the capacity specified by high watermark is identical to the total available storage capacity of the optical disk (that is, the high watermark is 100%), then the sequential mode is used. Except for the above case, the capacity to store data cannot exceed the high watermark. 
     Therefore, the reason for adopting the high watermark for the storage side of an optical disk is to obtain spare capacity to store additional data to the identical side of the optical disk, to the extent that it is possible, when trying to store additional data which is related to existing stored data. 
     FIG. 6 illustrates a method for storing data by utilizing a high watermark for the optical disk according to the present invention. 
     If a request to store data to an optical disk occurs in step s 601 , the stored high watermark is read from the storage media information database by a request to search the database information, and the sum of the data used at the corresponding optical disk and the requested data is compared to the capacity assigned by the high watermark in step s 602 . After the latter data are compared, if the capacity assigned by the high watermark is greater than the sum of the data used at the corresponding optical disk and the requested data, then the data is stored to the optical disk, and the total used capacity is computed in step s 607  (since this means that the optical disk has sufficient empty capacity). 
     After the above data are compared, if the capacity assigned by the high watermark is equal to or less than the sum of the data used at the corresponding optical disk and the requested data, this means that the capacity specified by the high watermark is fully occupied. Therefore, it must be determined whether the above request applies to a case in which data must be stored to an identical side of an optical display modifying the high watermark (e.g., when storing data, related to existing stored data, to an identical side) in step s 603 . 
     If, based on the latter determination, it is not necessary to store the data to an identical side, then the data is stored to another available optical disk in step s 606 . 
     Furthermore, if it is not necessary to store data to an identical side, then the sum of the data used at the corresponding optical disk and the requested capacity is compared to the available capacity of the optical disk in step s 604 . 
     If, based on the latter comparison, the available capacity is greater than the sum of the data used at the corresponding optical disk and the requested data, then the high watermark is automatically modified by an amount equal to the sum of the data used at the corresponding optical disk and the requested capacity, and the data is stored to the identical side of the optical disk in step s 605 . 
     Furthermore, if the available capacity is not greater than the sum of the data used at the corresponding optical disk and the requested data, then the data is stored to another available optical disk in step s 606 . 
     It should be understood that the present invention is not limited to the particular embodiment disclosed herein as the best mode contemplated for carrying out the present invention, but rather that the present invention is not limited to the specific embodiments described in this specification except as defined in the appended claims.