Abstract:
The invention relates generally to archiving data items in an information store. More particularly, the invention provides a computerized method for identifying, in a first information store, a first data item satisfying retention criteria; copying the first data item to a second information store; creating, in the first information store, a second data item containing a subset of the data of the first data item selected based on the data tvpe of the first data item; and replacing the first data item, in the first information store, with the second data item.

Description:
PRIORITY CLAIM  
       [0001]     This application claims priority from U.S. Provisional Patent Application No. 60/326,023, entitled “APPLICATION SPECIFIC OBJECT ARCHIVING AND RETRIEVAL SYSTEM”, filed Sep. 28, 2001. The entire contents of the Provisional Application 60/326,023 are hereby incorporated herein by reference in their entirety.  
       RELATED APPLICATIONS  
       [0002]     This application is related to the following pending applications: 
        application Ser. No. 09/610,738, titled MODULAR BACKUP AND RETRIEVAL SYSTEM USED IN CONJUNCTION WITH A STORAGE AREA NETWORK, filed Jul. 6, 2000, attorney docket number 044463-002;     application Ser. No. 09/609,977, titled MODULAR BACKUP AND RETRIEVAL SYSTEM WITH AN INTEGRATED STORAGE AREA FILING SYSTEM, filed Aug. 5, 2000, attorney docket number 044463-0023;     application Ser. No. 09/354,058, titled HIERARCHICAL BACKUP AND RETRIEVAL SYSTEM, filed Jul. 15, 1999, attorney docket number 044463-0014;     application Ser. No. 09/774,302, titled LOGICAL VIEW WITH GRANULAR ACCESS TO EXCHANGE DATA MANAGED BY A MODULAR DATA AND STORAGE MANAGEMENT SYSTEM, filed Jan. 30, 2001, attorney docket number 044463-0040;     application Ser. No. 09/876,289, titled APPLICATION SPECIFIC ROLLBACK IN A COMPUTER SYSTEM, filed Jun. 6, 2000, attorney docket number 044463-0029;     application Ser. No. 09/774,272, titled EMAIL ATTACHMENT MANAGEMENT IN A COMPUTER SYSTEM, filed Jan. 30, 2001, attorney docket number 4982/15;     application Ser. No. 09/882,438, titled STORAGE OF APPLICATION SPECIFIC PROFILES CORRELATION TO DOCUMENT VERSIONS, filed Jun. 14, 2001, attorney docket number 4982/16; and     application Ser. No. ______, Titled COMBINED STREAM AUXILIARY COPY SYSTEM AND METHOD, filed Sep. 16, 2002, attorney docket number 4982/26Prov;        
 
         [0011]     each of which is hereby incorporated by reference in this application in its entirety. 
     
    
     COPYRIGHT NOTICE  
       [0012]     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosures, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.  
       BACKGROUND OF THE INVENTION  
       [0013]     The invention disclosed herein relates generally to object archiving and retrieval in computer systems.  
         [0014]     Electronic mail (e-mail) has increasingly become a common and accepted manner of exchanging messages for individuals both at home and in the workplace. Indeed, some e-mail users send and receive hundreds or even thousands of messages each day. Managing this large volume of message traffic, however, has become a problem for both individual users and network administrators.  
         [0015]     When messages are sent and received by a mail application, they are stored for review in folders which are typically part of a file commonly referred to as an e-mail information store (“IS”) that is designated to hold e-mail stored on the user&#39;s local computer or on a network storage device. Other types of applications such as directory services applications also have information stores which contain data specific to particular applications.  
         [0016]     Over time, the IS typically grows in size as the user continues to receive and send more e-mail. This constantly increasing growth is problematic. Unless steps are periodically taken to reduce its size, the IS will eventually grow so large that it will use considerable amounts of disk space and also require excessive system resources to access its information. To keep the size of the IS under control and optimize system performance, administrators and users of e-mail systems have had to either delete or archive old or unwanted messages to release disk space. Both of these methods have serious drawbacks.  
         [0017]     One problem associated with archiving old messages is that the archived messages are normally stored on the user&#39;s workstation in file formats such as .PST files which are difficult to manage. All references to individual messages archived to .PST files no longer appear in the inbox and these individual messages are no longer readily accessible by browsing the e-mail client GUI In order to review individual archived messages, users must know which archive contains their message and must open the individual archive containing the message before being able to access the message contents. This process is often time-consuming with users frequently resorting to trial-and-error methods of opening archives to locate desired messages.  
         [0018]     Deleting old or unwanted messages is an even less desirable solution than archiving such messages. While archive files are difficult to manage and to retrieve messages from, deleting old or unwanted messages makes management and retrieval even more difficult and frequently impossible. If the user has performed a system backup prior to deleting such messages, retrieval is sometimes still possible, but the user must then restore the entire the entire system from the backup to retrieve the messages. In the worst case, the messages are simply lost forever when they are deleted.  
         [0019]     Further, even in a networked environment with a central e-mail sever such as, for example, a Microsoft Exchange Server, which contains a central IS, the normal backup process will also not directly help cut down the size of the IS. Backing up the IS will still leave all of the messages in the IS unless the individual users delete or archive messages at their workstations.  
         [0020]     There is thus a need for a system which permits users to easily manage archiving and retrieving e-mail messages.  
         [0021]     In addition, similar problems relating to archiving of old or unwanted objects exist in other directory services applications such as Microsoft&#39;s Active Directory, the University of Michigan&#39;s LDAP Servers, Lotus Notes, Microsoft&#39;s Sharepoint Portal, and other similar applications. In each of these applications, there exists a database similar to the Exchange IS which is constantly growing over time. System administrators must decide how much data in these databases is actually needed, how much should be archived, etc. One problem with archiving an entire directory services application database is that on restore, the entire database generally needs to be shut down even if only a small portion of the database needs to be restored. More single file restores are done than full system restores which results in inefficient use of system resources among other problems. There is thus also a need for a system which permits users to easily manage archiving and retrieving directory services and other similar application objects.  
       SUMMARY OF THE INVENTION  
       [0022]     The present invention addresses the problems discussed above with the management of archiving and retrieving application specific archiving and retrieval.  
         [0023]     In accordance with some aspects of the present invention, computerized methods are provided for archiving data, the methods comprising identifying, in a first information store, a first data item satisfying a retention criterion; copying the first data item from the first information store to a second information store; creating, in the first information store, a second data item containing a subset of the data of the first data item selected based on the data type of the first data item; and replacing the first data item, in the first information store, with the second data item. In some embodiments, the first data item may comprise an electronic mail message, an attachment to an electronic mail message, a directory services entry, or other data objects.  
         [0024]     The retention criteria is a property or characteristic of the first data item used by the invention to select the first data item for archiving and other purposes. In some embodiments. the retention criterion comprises a first creation date and identifying the first data item comprises comparing a first creation date of the first data item to the creation date specified as the retention criteria. In some embodiments, the retention criterion comprises a last accessed date and identifying the first data item comprises comparing a last accessed date of the first data item to the last accessed date specified as the retention criteria. In some embodiments, the retention criterion comprises an item size and identifying the first data item comprises comparing an item size of the first data item to the item size specified as the retention criteria.  
         [0025]     In some embodiments, the first information store may comprise an electronic mail information store, a directory services information store, or other type of information store. In some embodiments, the second information store is a secondary storage device. In some embodiments, the second data item contains index information identifying a location of the first data item in the second information store.  
         [0026]     In some embodiments, the second data item may comprise an electronic mail message, a directory services entry, or other type of data object. In some embodiments, the second data item contains header fields of the first data item which may include, for example, in the case of an electronic mail message, a sender field, a recipient field, a subject field, a date field, and a time field. In some embodiments, the second data item contains a subset of the message body of the first data item. In some embodiments, the second data item contains a message body specified by a user. In some embodiments, replacing the first data item comprises deleting the first data item from the first information store.  
         [0027]     In one embodiment, the invention provides a system for archiving data, the system comprising a first information store containing one or more data items; a second information store; and a computer, connectable to the first information store and the second information store; wherein the computer is programmed to identify, in the first information store, a first data item satisfying a retention criteria; to copy the first data item to the second information store; to create, in the first information store, a second data item containing a subset of the data of the first data item selected based on the data type of the first data item; and to replace the first data item from the first information store. In some embodiments, the computer is programmed to identify an electronic mail message, an attachment to an electronic mail message, a directory services entry, and combinations thereof In some embodiments, the computer is programmed to replace the first data item from the first information store by deleting the first data item.  
         [0028]     In one embodiment, the invention provides a computer usable medium storing program code which, when executed on a computerized device, causes the computerized device to execute a computerized method for archiving data, the method comprising identifying, in a first information store, a first data item satisfying a retention criterion; copying the first data item from the first information store to a second information store; creating, in the first information store, a second data item containing a subset of the data of the first data item selected based on the data type of the first data item; and replacing the first data item, in the first information store, with the second data item.  
         [0029]     In one embodiment, the invention provides a system for archiving data comprising a plurality of application-specific data agents each configured to coordinate archiving of first data items used in a particular software application; and a plurality of application-specific stubbing modules each funtinctionally integrated with a corresponding application-specific data agent, each stubbing module being configured to replace a first data item used in the corresponding software application with a second data item used in the corresponding software application and representing a subset of the first data item. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]     The invention is illustrated in the figures of the accompanying drawings which are meant to be exemplary and not limiting, in which like references are intended to refer to like or corresponding parts, and in which:  
         [0031]      FIG. 1  is block diagram of a network architecture for a system to archive and retrieve application specific objects according to embodiments of the invention;  
         [0032]      FIG. 2  is high-level flow chart of a method to archive application specific objects according to embodiments of the present invention;  
         [0033]      FIG. 3  is a detailed flow chart of a method to archive application specific objects according to embodiments of the present invention;  
         [0034]      FIG. 4  is a flow chart of a method to restore application specific objects according to embodiments of the present invention; and  
         [0035]      FIG. 5  is an exemplary screen display of an e-mail message stub from a system to archive and retrieve application specific objects according to embodiments of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]     Embodiments of methods and systems according to the present invention are described through references to FIGS.  1  though  5 . A network architecture for a system to archive and retrieve application specific objects in accordance with embodiments of the present invention is depicted in  FIG. 1 . As shown, the system includes a storage manager  125  and one or more of the following: a data agent  105 , a client computer  107 , a first information store  108 , a stubbing module  109 , a media agent  110 , a secondary storage library  115 , and an index cache  120 . The system and elements thereof are exemplary of a three-tier backup system such as the CommVault Galaxy backup system, available from CommVault Systems, Inc. of Oceanport, N.J., and further described in application Ser. No. 09/610,738 which is incorporated herein by reference in its entirety.  
         [0037]     A data agent  105  is a software module that is generally responsible for archiving, migrating, and recovering data of a client computer  107 . Each client computer  107  has at least one data agent  105  and the system can support many client computers  107 . The system provides a plurality of data agents  105  each of which is intended to backup, migrate, and recover data associated with a different application. For example, different individual data agents  105  may be designed to handle Microsoft Exchange data, Lotus Notes data, Microsoft Windows 2000 file system data, Microsoft Active Directory Objects data, and other types of data known in the art. If a client computer  107  has two or more types of data, one data agent  105  is required for each data type to archive, migrate, and restore the client computer  107  data. For example, to backup, migrate, and restore all of the data on a Microsoft Exchange 2000 server, the client computer  107  would use one Microsoft Exchange 2000 Mailbox data agent  105  to backup the Exchange 2000 mailboxes, one Microsoft Exchange 2000 Database data agent  105  to backup the Exchange 2000 databases, one Microsoft Exchange 2000 Public Folder data agent  105  to backup the Exchange 2000 Public Folders, and one Microsoft Windows 2000 File System data agent  105  to backup the client computer&#39;s  107  file systel These data agents  105  are addressed as four separate data agents  105  by the system even though they reside on the same client computer  107 .  
         [0038]     The data stubbing module  109  is a component of the media agent that performs stubbing operations on data items as further described herein.  
         [0039]     A media agent  110  conducts data between the client computer  107  and one or more storage libraries  115  such as a tape library or other storage device. The media agent  110  is communicatively coupled with and controls the storage library  115 . For example, the media agent  110  might instruct the storage library  115  to use a robotic arm or other means to load or eject a media cartridge, and to archive, migrate, or restore application specific data. The media agent  110  generally communicates with the storage library  115  via a local bus such as a SCSI adaptor. In some embodiments, the storage library  115  is communicatively coupled to the data agent  110  via a Storage Area Network (“SAN”).  
         [0040]     Each media agent  110  maintains an index cache  120  which stores index data the system generates during backup, migration, and restore storage operations as further described herein. For example, storage operations for Microsoft Exchange data generate index data. Index data is useful because it provides the system with an efficient mechanism for locating user files for recovery operations. Although this index data is generally stored with the data backed up to the storage library  115 , the media agent  110  that controls the storage operation also writes an additional copy of the index data to its index cache  120 . The data in the index cache  120  is thus readily available to the system for use in storage operations and other activities without having to be first retrieved from the storage library  115 .  
         [0041]     Each index cache  120  typically resides on the corresponding media agent&#39;s  110  hard disk or other fixed storage device. Like any cache, the index cache  120  has finite capacity and the amount of index data that can be maintained directly corresponds to the size of that portion of the disk that is allocated to the index cache  120 . In one embodiment, the system manages the index cache  120  on a least recently used (“LRU”) basis as known in the art. When the capacity of the index cache  120  is reached, the system overwrites those files in the index cache  120  that have been least recently accessed with the new index data. In some embodiments, before data in the index cache  120  is overwritten, the data is copied to the index cache  120  copy in the storage library  115 . If a recovery operation requires data that is no longer stored in the index cache  120  such as in the case of a cache miss, the system recovers the index data from the index cache  120  copy stored in the storage library  120 .  
         [0042]     The storage manager  125  is a software module or application that coordinates and controls the system. The storage manager  125  communicates with all elements of the system including media agents  110 , client computers  107 , and data agents  105  to initiate and manage system backups, migrations, and recoveries.  
         [0043]     In some embodiments, components of the system may reside and execute on the same computer. In some embodiments, a client computer  107  component such as a data agent  105 , a media agent  110 , or a storage manager  125  coordinates and directs local archiving, migration, and retrieval application finctions as further described in application Ser. No. 09/610,738. This client computer  107  component can function independently or together with other similar client computer  107  components.  
         [0044]      FIG. 2  presents high-level flow chart of a method to archive application specific objects in accordance with embodiments of the present invention. An archive job automatically starts, step  130 , according to a pre-defined schedule or as manually directed by a user. In some embodiments, the storage manager  125  instructs the media agent  110  to begin an archive job and the media agent  110  then instructs the data agent  105  to commence an archive process. In other embodiments, the media agent  110  directly instructs the data agent  105  to commence an archive process without instructions from the storage manager  125 .  
         [0045]     The archive process filters and archives those messages, objects, or other data items in a first information store  108  according to specified retention criteria, step  135 . In some embodiments, the retention criteria may be input directly by a user when the archive job is started. In other embodiments, the retention criteria may be pre-defined or calculated automatically according to user preferences or other information and the archive job proceeds autonomously. Those messages, objects, or other data items that fulfill the specified retention criteria are copied from the first information store  108  to a second information store. In some embodiments, the second information store is located on secondary storage media such as a storage library  115 .  
         [0046]     A stubbing process creates a stub for and deletes each message in the first information store  108  that was copied to the second information store, step  140  As used herein, stubs are data objects that replace messages, objects, and other data items in the first information store  108  that were copied to the second information store. Copying the messages to the second information store frees storage space in the first information store  108 . Stubs that replace the copied messages generally require less storage space and indicate which items were copied and deleted from the first information store  108 . Stubs also facilitate retrieval of messages that were copied to the second information store.  
         [0047]     When all items in the first information store  108  have been archived and stubbed or when directed by a user, the job ends, step  145 .  
         [0048]      FIG. 3  presents detailed flow chart of a method to archive application specific objects in accordance with embodiments of the present invention. A job manager starts an archiving job beginning with an archiving phase and notifies an archive management daemon on the client computer  107 , step  150 . The job manager is a software process that is generally a part of the storage manager  125 , but in some embodiments the job manager may also be part of the media agent  110 , the data agent  105 , or any combination thereof. In some embodiments, the system starts with the archiving phase to ensure that messages, objects, or other data items are only stubbed after they are backed-up to secondary storage. Those skilled in the art will recognize that multiple archiving jobs could be run at one time.  
         [0049]     As previously described herein, archive jobs can either be started manually as directed by a user or automatically as a scheduled system management task. In some embodiments, archive jobs may take place according to schedule policies as further described in application Ser. No. 09/882,438 which is incorporated herein by reference in its entirety. For example, a schedule policy may indicate that archive jobs should take place on a specified information store once per day at a particular hour or at other designated times. In some embodiments, the archiving process and stubbing process can also be scheduled at off-peak times to reduce the load to system resources.  
         [0050]     The archive management daemon initiates an archiving process of the data agent  105 . step  155 . which archives messages, objects, or other data items in a first information store  108  according to specified retention criteria.  
         [0051]     The archiving process scans an item in the first information store  108  to determine whether the item fulfills the retention criteria, step  160 . For example, in an e-mail information store, the archiving process scans the mailboxes in the IS  108  to find candidate messages or objects meeting either the default retention criteria, such as the retention criteria specified in a storage policy, or the retention criteria customized by the user.  
         [0052]     As previously described, retention criteria define archiving rules for the archiving process to control the content of stubs, which messages, objects, or other data items get archived, the retention time for stubs and archived messages, objects, or other data items, and other similar filtration criteria. In one embodiment, messages, objects, and other data items are copied to secondary storage according to parameters such as job ID, times, etc. In other embodiments, retention criteria specify additional options to indicate whether a stub should be left behind or not, whether the entire message or object or just the attachment should be archived, and other similar choices. In some embodiments, retention criteria specify a mailbox size threshold and exclusion filter for mailbox(es) or folder(s), so that only mailboxes whose size exceed the threshold and are not in the filter list will be scanned. In some embodiments, retention criteria also specify rules based on message creation time, modification time, size, or attachment(s) to further control the message selection criteria. For example, messages in the IS  108  that satisfy certain retention criteria such as age, size, size of attachments, amount of disk space left, size of mailbox, etc. are archived to secondary storage  115 .  
         [0053]     Since stubs are usually new small messages or objects with no attachments, they can be difficult to remove from a users mailbox. To facilitate stub management among other things, retention criteria also define the lifetime of a stub in some embodiments. After a stub expires past its lifetime, the next archiving job will either delete the stub from the first information store  108  or archive the stub to secondary storage such as a storage library  115 .  
         [0054]     The size of index cache  120  may grow over time and in some embodiments, archive pruning-related retention criteria specifies that data should be pruned or deleted in the first information store  108  and also in the index cache  120 . In some embodiments, retention criteria may also specify whether archived messages, objects, and other data items in secondary storage  115  should be pruned after additional time has passed or at any desired point.  
         [0055]     In some embodiments, retention criteria specifies that there should be no orphan stubs left in the IS  108 . In one embodiment, this goal among others is achieved by using retention times, such that stubs always expire before their related messages, objects, or other data items archived in secondary storage  115 . In other embodiments, retention criteria specifies that items archived in secondary storage  115  are not pruned if a stub still exists in the first information store  108 . In an alternate embodiment, archive pruning of secondary storage  115  items produces a pruned list stored in the index cache  115  or other information store and the system uses this list to then remove the related stubs remaining in the first information store  108 . In some embodiments, however, retention criteria may permit messages archived in secondary storage to be pruned even if a related stub still exists in the first information store  108 .  
         [0056]     If the item scanned fulfills the retention criteria, step  165 , the archiving process writes a copy of the message, object, or other data item to secondary storage  115 , step  170 , as further described in application Ser. No. 09/610,738 and application Ser. No. 09/609,977 which are incorporated herein by reference in their entirety. To make the restore process faster and to achieve other desirable goals, messages, objects, and other data items can first be archived on a magnetic library. Later these items can be moved to tape or some other storage media for long-term storage. In one embodiment, data may be moved from a magnetic library to tape or some other secondary storage media using auxiliary copy to further conserve system resources, and as described in application Ser. No. ______, COMBINED STREAM AUXILIARY COPY SYSTEM AND METHOD, filed Sep. 16, 2002, attorney docket number 4982/26Prov, which is incorporated herein by reference in its entirety.  
         [0057]     Identifying characteristics and other information about the item copied to secondary storage  115  are recorded to an archiving list stored in a local information store of the data agent  105 , step  175 . During the archiving phase, a record detailing information about every item successfully copied from the first information store  108  to secondary storage  115  will be stored in the archiving list which serves as input and is used during the stubbing phase as further described herein. The content of items in the archiving list include information for the later stubbing phase and restore process to locate the original archived messages, objects, or other data items. Examples of such information include mailbox name, folder ID, message ID, and link information to the item&#39;s secondary storage location. An example of such link information is a Universal Naming Convention (“UNC”) path to the item&#39;s index entry in a Galaxy file system.  
         [0058]     The system determines whether additional items remain in the first information store  108  to be scanned against the retention criteria, step  180 . If additional items remain to be scanned, then control returns to step  160 , and the process repeats. Otherwise, the archiving process terminates and the job manager then starts the archiving index phase writing the archive information to the index cache  115  on a media agent  110  or other component, step  185 , as further described in application Ser. No. 09/610,738 which is hereby incorporated by reference in its entirety.  
         [0059]     When the archiving index phase is complete, the media agent notifies the job manager which then initiates a stubbing process, step  190 . The stubbing process retrieves the archiving list of messages, objects, or other data items created during the archiving process to use as input during the stubbing phase and sequentially processes each item on the archiving list, step  195 . While the stubbing process could query the media agent  110  containing the index cache  115  created during the archiving index phase, this option is less desirable due to the network and processor resources required. A more desirable method, as described herein, combines archiving and stubbing into a single job in which the stubbing phase only starts after the archiving phase is successfully completed. In one embodiment, the stubbing phase processes items on the archiving list based on application ID, job status, and other criteria.  
         [0060]     In some embodiments, before a stub is created, the system prompts for, step  200 , and accepts, step  205 , user input of text and other information to display or otherwise associate with a stub.  
         [0061]     For each item on the archiving list, the stubbing process then creates a new “stub” message, object, or other data item in the first information store  108 , step  210 . Each new message has the same data structure as the original message, except the body field of the message is replaced with explanation text or other information indicating that the message is a stub, and a path linking to the archived message.  
         [0062]     New stubs are generally created according to stub configuration options specified in the storage policy associated with the first information store  108 . Stub configuration options include stub with no body or stub with full body, but no attachment, etc. The subject of the stub can be changed to incorporate a tag or other parsable identifier such as “&lt;archived&gt;original subject” so that subsequent archive operations can identify the stub. In some embodiments, there are also named properties in stubs. In some embodiments, stubs contain an ID and an archive time to assist backup systems such as Galaxy with stub management.  
         [0063]     After each stub is successfully created, the stubbing process deletes the original message, step  215 , and determines whether there are additional items to process on the archiving list, step  220 . If additional items remain to be processed, control returns to step  195 . Otherwise, once all messages, objects, and other data items on the archiving list have been processed, the stubbing process returns control to the job manager and the archiving job terminates, step  225 .  
         [0064]      FIG. 4  presents a flow chart of a method to restore application specific objects according to embodiments of the present invention. The message, object, or other data item to restore is selected, step  230 . The item may be selected automatically by the system according to predefined restore criteria stored in the index cache  115 , in a storage policy, or in another information store. The system also acccpts user input to manually select the item to restore.  
         [0065]     Turning to  FIG. 5 , for example, a sample screen display shows an e-mail message stub from a system to archive and retrieve application specific objects according to embodiments of the present invention. As shown, the stub includes many of the header fields of the original archived message including the sender  260 , the recipient  265 , the subject  270 , and the time/date  275 . The stub also includes a message  280  indicating that the body of the original message has been archived, a link  285  to the archived message body, a message  290  indicating that an attachment to the original message has been archived, and a link  295  to the archived attachment.  
         [0066]     In one embodiment, items archived in secondary storage, such as the message body, can be restored by manually clicking on the UNC link  285  or other identifying path in the item&#39;s related stub. The stub message ID is encoded within the link  285 . The media agent  210  or the data agent  205  detects the click, parses the message ID, and passes the ID as a parameter to the restore process, as further described herein.  
         [0067]     If an archived e-mail message&#39;s corresponding stub is still in a mailbox or other browsable first information store  108 , a user can search on the stubs&#39; fields copied from the archived e-mail message including the sender  260 , recipient  265 , subject  270 , time/date  275 , and other identifying criteria to find the corresponding stub. In some embodiments, stubs with full bodies can also be located via full-text (index) searching functions of a mail server or other file system.  
         [0068]     Sometimes, stubs will no longer be accessible via the first information store  108 . For example, stubs may have been pruned or otherwise deleted. In another embodiment. the archived message can be selected via the archive message&#39;s index entry in a secondary storage file system such as in the Galaxy system. For example, if the user wants to restore an archived e-mail message whose corresponding stub has been pruned from the first information store  108  mailbox, the user can still restore the archived e-mail via a backup system console browser such as the Galaxy console browser.  
         [0069]     As further described in application Ser. No. 09/610,738 and application Ser. No. 09/609,977 which are incorporated herein by reference in their entirety, selecting an item to restore triggers the media agent  210  mapped storage installable file system, and the media agent  210  sends a restore request to a job manager process on the media agent, step  235 . The job manager on the media agent  210  starts a restore job using the information contained in the request and notifies a job manager process of the data agent  205 , step  240 . The job manager process of the data agent  205  creates a restore process which retrieves the archived message from the secondary storage library  115  returning it to the first information store  108 , step  245 . After the archived item is restored from secondary storage  115  and copied to the first information store  108 , the item&#39;s corresponding stub is deleted from the first information store  108 , step  250 , and the job ends, step  255 .  
         [0070]     In some embodiments, users are prevented from modifying stubs since the restore process depends on special information contained in each stub to identify it as a stub and to restore the original message.  
         [0071]     In one embodiment, if users are moved to another mail server having a different information store than the first information store  108 , the system first restores all the stubbed messages, objects, and other data items back to the user&#39;s mailbox in the first information store  108 . and then deletes all the stubs before the administrator is permitted to move the user. In some embodiments, this is accomplished as an integrated part of the system or as a separate process to scan the mailbox in the first information store  108 , find all the stubs, pass the links to the media agent  119  to start a restore job, and then delete the stubs. In some embodiments, stubs contain application type, backup management system console information such as CommVault CommServer information, and other information which ensures compatibility and continued functionality of the invention if a user updates their mail server.  
         [0072]     While the system has frequently been described above in the context of electronic mail object archiving, the system also archives and restores general directory services client objects for each entry that exists in a service such as Microsoft&#39;s Active Directory, the University of Michigan&#39;s LDAP Servers, Lotus Notes, Microsoft&#39;s Sharepoint Portal, and other similar applications. Attributes and properties of each archived service entry are retained in the corresponding stub. Client operations are performed using an interface such as the Windows LDAP API, which can interface with Active Directory, as well as any other LDAP compliant directory service. Similarly, the directory services client looks and behaves very much like an e-mail file system agent from a GUI standpoint with backup sets and sub-clients where default sub-clients backup the entire directory service and new sub-clients are defined to limit the scope of the backup. Filters specify retention criteria to archive certain branches of the directory tree, certain entries, and certain attributes. Each entry is stored in a separate file that adheres to the interface format, such as the LDIF (LDAP Data Interchange Format) format, which is an RFC standard format for listing the attributes of an entry.  
         [0073]     Systems and modules described herein may comprise software, firmware, hardware, or any combination(s) of software, firmware, or hardware suitable for the purposes described herein. Software and other modules may reside on servers, workstations, personal computers, computerized tablets, PDAs, and other devices suitable for the purposes described herein. Software and other modules may be accessible via local memory, via a network, via a browser or other application in an ASP context, or via other means suitable for the purposes described herein. Data structures described herein may comprise computer files, variables, programming arrays, programming structures, or any electronic information storage schemes or methods, or any combinations thereof, suitable for the purposes described herein. User interface elements described herein may comprise elements from graphical user interfaces, command line interfaces, and other interfaces suitable for the purposes described herein. Screenshots presented and described herein can be displayed differently as known in the art to input, access, change, manipulate, modify, alter, and work with information.  
         [0074]     While the invention has been described and illustrated in connection with preferred embodiments, many variations and modifications as will be evident to those skilled in this art may be made without departing from the spirit and scope of the invention, and the invention is thus not to be limited to the precise details of methodology or construction set forth above as such variations and modification are intended to be included within the scope of the invention.