# Patent

## Title
Method, system, and program implementing retention policies to archive records

## Abstract

Provided are a method, system, and program for receiving a request to remove a record. A determination is made as to whether a state associated with the record includes at least one hold state and whether the state associated with the record includes at least a retention period that has not expired. The request to remove the record is denied in response to determining that the state associated with the record includes at least one of at least one hold state and one retention period that has not expired.

## Background
RELATED APPLICATIONS
This patent application is a continuation of U.S. patent application Ser. No. 11/465,630, filed on Aug. 18, 2006 and issued as U.S. Pat. No. 7,526,621 on Apr. 28, 2009, which is a continuation of application Ser. No. 10/737,367, filed Dec. 15, 2003, now U.S. Pat. No. 7,107,416, issued on Sep. 12, 2006, which is a continuation-in-part of application Ser. No. 10/681,558, filed Oct. 7, 2003, now both U.S. Pat. No. 7,146,388, issued on Dec. 5, 2006, and application Ser. No. 10/658,487 filed Sep. 8, 2003, now U.S. Pat. No. 7,117,322, issued on Oct. 3, 2006, wherein all related patent applications are incorporated herein by reference in their entirety.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method, system, and program for implementing retention policies to archive records.
2. Description of the Related Art
Organizations may need to retain and archive electronic files (where a file comprises a document, record, or any other data structure storing code or data that may be represented in a hierarchical file system) in storage for an extended period of time due to internal corporate requirements or external regulatory or legal requirements. For instance, government regulators may require that certain files remain archived for a minimum period of time. Companies in regulated industries, such as securities and financial organizations, defense contractors, etc., may be required to archive certain documents. Further, government agencies may also be required to archive files. Yet further, organizations subject to a government proceeding, such as litigation, may also be subject to a file retention policy. An organization may also archive documents for backup and storage, and versioning. A storage system often includes some archival software to manage the archival of files at different locations that are retained according to a policy. Such archival software may maintain a database of archived files. Use of the archival software may require significant user training and management, as well as a stand alone application program. Archival software typically features customized graphical user interfaces (GUIs) and application program interfaces (APIs) to interface with the operating system to perform archival related operations.
One archival data storage technology referred to as WORM (for write once, read many) involves archiving data to a storage media, such as optical disks, that can only be written to once. One disadvantage of using optical disks is that their access rates are slow, especially when the disks are maintained in an auto-changer that needs to mechanically access a disk from a slot and insert the accessed disk into a disk drive to access.
To avoid some of the drawbacks of using optical disks, some archival system vendors are using inexpensive hard disk drives as the medium for archiving data. The hard disk drive storage system is sold bundled with software to expose the storage as a proprietary archive utility, requiring custom interfaces and application program interfaces to use the archival features.



BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 illustrates a computing environment in which embodiments of the invention are implemented;
FIG. 2 illustrates an example of an arrangement of a hierarchical file system in accordance with implementations of the invention;
FIGS. 3, 4, and 5 illustrate an example of operations performed to manage archived files in accordance with implementations of the invention;
FIG. 6 illustrates an alternative implementation of the archival system in accordance with implementations of the invention;
FIG. 7 illustrates metadata on a record providing information on a retention policy associated with that record in accordance with implementations of the invention;
FIG. 8 illustrates a retention policy state machine in accordance with implementations of the invention;
FIGS. 9, 10, and 11 illustrate operations performed to implement a retention policy in accordance with implementations of the invention;
FIG. 12 illustrates a computing architecture that may be used to implement the computing environments described with respect to FIGS. 1 and 6.



SUMMARY
Provided are a method, system, and program for receiving a request to remove a record. A determination is made as to whether a state associated with the record includes at least one hold state and whether the state associated with the record includes at least a retention period that has not expired. The request to remove the record is denied in response to determining that the state associated with the record includes at least one of at least one hold state and one retention period that has not expired.
Provided are a method, system, and program for receiving a request to remove a record. A determination is made as to whether a state associated with the record includes at least one event state or whether the state associated with the record includes at least a retention period that has not expired. The request to remove the record is denied in response to determining that the state associated with the record includes at least one of the event state and one retention period that has not expired.
DETAILED DESCRIPTION
In the following description, reference is made to the accompanying drawings which form a part hereof and which illustrate several embodiments of the present invention. It is understood that other embodiments may be utilized and structural and operational changes may be made without departing from the scope of the present invention.
Applying a Retention Policy
FIG. 1 illustrates a computing environment in which embodiments of the invention are implemented. A host system 2 includes an operating system 4 and a file system 6 that provides an organization of files stored in a storage device. The file system 6 may implement a hierarchical tree-like arrangement of files, which may involve the use of directories and subdirectories in which the files or records may be stored, where any directory may comprise a subdirectory of another directory or the root directory. A file system user interface 8 provides a command line or graphical user interface to enable the user to explore the file system and perform file system related operations, such as moving a file to a specified directory, deleting a file, renaming a file, creating a file, etc. The file system user interface 8 may comprise a file management program that renders a presentation of the hierarchical arrangement of files. The file system user interface 8 may comprise a stand-alone file management program or a file management function accessed through an application program.
An archival filter 10 intercepts user file requests generated through the file system user interface 8 directed to the file system 6 and determines whether any archival retention policies should block such user requested operation if necessary or allow the operation to proceed to the file system 6 to execute. The file system 6 may provide access to files stored in the storage system 12 via connection 14.
The host system 2 may comprise any computing device known in the art, such as a server class machine, workstation, desktop computer, etc. The storage system 12 may comprise any storage device known in the art, such one or more interconnected disk drives configured as a Redundant Array of Independent Disks (RAID), Just a Bunch of Disks (JBOD), Direct Access Storage Device (DASD), as a tape storage device, a single or multiple storage units, e.g., a tape library, or etc. The connection 14 may comprise any interface between storage and a host known in the art, such as a network connection (e.g., Ethernet, wireless Ethernet, Fibre Channel, etc.) or any other data transfer interface known in the art, e.g., Advanced Technology Attachment (ATA), Serial ATA (SATA), Small Computer System Interface (SCSI), etc., which may be external or internal to the host 2 enclosure.
In certain embodiments, the archival filter 10 determines the retention policies based on a pathname of a directory associated with a retention policy. For instance, to indicate that files or records within a directory are to be retained for a specified time period, the user may name a directory “/RetainX”, where X specifies a time period, e.g., years, days, months, etc. In certain implementations, the action of “retaining” a file may entail never allowing the file to be modified or updated in any circumstances, and only permitting erase and move operations. The retention policy indicated in the pathname of the directory would apply to any files or records stored within the directory having the retention pathname or any further subdirectory of the directory having the retention name. FIG. 2 illustrates a hierarchical tree file system in which data is organized having two directories 30 and 32. The archival policy specified in the pathnames of the retention directories 30 and 32 may apply to files stored in the retention directories 30 and 32 or any subdirectories defined therein. The user may use the file system user interface 8 to move files to a retention directory, such as by using an input device to “drag and drop” or otherwise move files from one directory to a retention directory 30 and/or 32 so that the retention policy will apply to the moved file.
Another example of a retention policy to use as the pathname is “RetainUntilX”, which specifies that files in a retention directory having such a pathname will be retained until the specified date “X”.
In this way, the user may use standard file management interfaces to associate a file with a retention policy by just copying or otherwise moving the desired file to a retention directory. With the described embodiments, specialized APIs or customized interfaces are not needed because a standard file management interface is used to specify the retention policies. Moreover, the user can define a retention policy by including descriptive language statements in the directory pathname, which are understood by the archival filter 10, that describe and specify the policy. This avoids the need for substantial training to instruct users on how to apply an archival policy to a file.
FIG. 2 illustrates an example of a hierarchical arrangement of directories, where the pathnames of the directories 30 and 32 provide a file retention policy to apply to all files in that directory. For instance any file within the directory 30 or a subdirectory of directory 30 will be retained for three years. When the date and time associated with a file, i.e., the last modification date, within the directory 30 is three years prior to the current date, then that file in the directory 30 may be deleted or moved without restriction. Similarly, any file in the path of a subdirectory of directory 32 will be retained for five years.
FIG. 2 also provides an example of a “hold” directory 34, which is a subdirectory of the retain directory 36 and litigation proceedings subdirectory 36. Any file moved to the hold directory 34 will not be allowed to be deleted, even after the expiration of the retention period indicated in the pathname of the directory 32. For instance, if certain files may be relevant to an imminent or pending litigation, then a hold directory 34 may be added as a subdirectory of the directory 36 to store files relevant to the litigation to prevent any files moved to the hold directory 34 from being deleted. A regulatory filings directory 38 archives files related to regulatory filings. In certain embodiments, a file in the hold directory 34 may be moved back to the directory from which it originated or another directory after the reason for the hold is no longer relevant.
FIG. 3 illustrates operations performed by the archival filter 10 to determine whether an archive policy applies to an operation to modify a file represented in the file system 6. The archival filter 10 would intercept and process a modify request before the request is sent to the file system 6 to execute. Upon receiving (at block 100) the request to modify the target file, if (at block 102) the target file to modify is not within a retention directory (directly or within a further subdirectory thereof), then the archival filter 10 passes (at block 104) the modify request to the file system 6 to execute. If the target file is within a retention directory, then the archival filter 10 returns (at block 106) a message indicating denial of the erase request due to a retention policy. The message may include additional information such as the specifics of the retention policy and the pathname of the directory including the target file.
With the logic of FIG. 3, any request to modify a file, as opposed to erase the file, may be denied regardless of whether the archival policy applies. This bar on modifying archived files regardless of the retention policy would prevent the situation from occurring where a file whose retention period expired is modified and subsequently subjected to a new archival retention policy. If such modification were allowed, then the new archival policy may be applied when the assumption is that the file subjected to the new archival policy was the previously archived file, not an updated version thereof.
FIG. 4 illustrates operations performed by the archival filter 10 to determine whether an archive policy applies to an operation to erase a file represented in the file system 6. The archival filter 10 would intercept and process an erase request before the request is sent to the file system 6 to execute. Upon receiving (at block 120) the request to erase the target file, if (at block 122) the target file to erase is not within a retention directory (directly or within a further subdirectory thereof), then the archival filter 10 passes (at block 124) the erase request to the file system 6 to execute. If the target file is within a retention directory, then a determination is made (at block 126) as to whether the retention policy specified in the pathname of the directory indicates an expirable retention period. A retention policy that does not expire may be indicated in the directory pathname with “hold”, retain forever, etc. If (at block 126) the retention policy does not expire, then the archival filter 10 returns (at block 128) a message indicating denial of the erase request due to a retention policy. The message may include additional information such as the specifics of the retention policy and the pathname of the directory including the target file. If (at block 126) the retention policy is for a defined, i.e., expirable, time period and if (at block 130) the retention period has expired, then control proceeds to block 124 to allow the erase request to proceed. Otherwise, if the retention period has not expired, then control proceeds to block 108 to return the message denying the erase request.
A retention period expires if the time period of the retention policy has been exceeded. For instance, if the retention period specifies a termination date, e.g., “RetainUntil—1/1/05”, then the retention period expires on the specific date. Alternatively, if the retention time period specifies a time frame, e.g., “Retain—3Years”, then the retention period expires when the current time exceeds the retention time period plus the time the file was created, last modified or added to the retention directory.
With the logic of FIG. 4, an erase operation is not allowed to proceed if a file is within a retention directory and the retention policy has not expired with respect to that target file. Thus, files with different creation/last modification dates may expire at different times according to certain retention policies specified in the directory file name. In this way, the archival filter 10 filters all erase requests. In certain implementations, the archival filter 10 would pass all read requests to the file system 6 to execute.
FIG. 5 illustrates operations performed by the archival filter 10 to process a request to move a target file from one directory to another. Upon receiving (at block 150) the request to move the target file, if (at block 152) the file is not within a directory whose file name specifies a retention policy, then the archival filter 10 passes (at block 154) the move request to the file system 6 to execute. If (at block 152) the target file is within a directory associated with a retention policy and if (at block 156) the retention policy does not specify an expirable retention time period, e.g., such as the case with the hold directory 34, then a determination is made (at block 158) whether the move is to a permitted directory. In certain implementations, a permitted target directory may be one whose files are associated with a retention policy that is as long or longer than the retention policy associated with the directory including the hold directory. For instance, in the example of FIG. 2, a file moved from the hold directory 34 would have to be moved to a directory having a retention policy of at least five years. In alternative implementations, a permitted directory may be associated with shorter retention time periods or no retention policies. If (at block 158) the move is to a permitted directory, then control proceeds to block 154 to pass the move command to the file system 6 to execute; otherwise, if the move is not to a permitted directory, then the archival filter 10 causes the return (at block 160) of a message indicating denial of the move due to a retention policy.
If (at block 156) the retention policy does provide an expirable (finite) time period and if (at block 162) the retention time period has expired, e.g., the specified termination date has passed or a termination period from the file date has expired, then control proceeds to block 154 to pass the move request to the file system 6 to execute. Otherwise, if the retention time period has not expired and if (at block 166) the target directory of the move has a same or longer retention policy than the retention policy of the directory currently including the target file, then control proceeds to block 154 to allow the file system 6 to execute the move request. If (at block 166) the target directory has a shorter retention time period than the current directory including the target file, then control proceeds to block 160 to deny the move request.
With the logic of FIG. 5, a file can be moved from a directory associated with a finite retention policy, i.e., one with an expirable time period, if the file is being moved to a directory having at least as long or longer than retention period. For instance, if a file is in a directory having a retain forever retention period, like the hold directory 34 (FIG. 2), then a file in that hold directory may only be moved to another hold directory also having the retain forever retention period. Further, if the file being moved is in a higher level directory, which contains the hold directory, then the file can only be moved to a hold directory within a higher level directory having the same or longer retention period of the higher level directory including the file subject to the move. This ensures that the file initially associated with the retention policy is retained for the specified period even after being moved. In further implementations, there may be a special directory for archived files removed from a retention directory to allow tracking of any files removed from the retention archives.
Certain of the described implementations provide techniques for using a standard file system interface to allow the user to implement a non-re-writable and non-erasable archival system, thereby avoiding the need to install, train for, and use a separate stand alone application program. With certain of the described implementations, the user specifies retention policies by associating retention policies with directories of the file system including the archived files to implement a non-re-writable and non-erasable environment.
Event Based Retention
FIG. 6 illustrates an additional computing environment in which embodiments of the invention are implemented. An archive server 170 maintains archive objects in archival storage 174, where the archived objects may originate from client systems 176a, 176b, 176c, where the clients 176a, 176b, 176c communicate objects to the archive server 170 over a network 180. The archive server 170 includes an archive program 182 which performs archive related operations, an archive database 184 maintaining records providing information on archived objects, and a retention protection setting 186 controlling the extent to which the archive program 182 permits users to remove or modify information in the archive database 184 and archived objects from the archival storage 174. In FIG. 6, the retention protection setting 186 comprises a global variable applying across all objects. In additional implementations, there may be separate protection settings for single objects or groups of objects, all objects in a node, filespace, from a client, etc. An object may comprise any data structure known in the art including data, such as a file, database, record, etc. All archive related operations are managed by the archive program 182 to ensure compliance with a configured archival policy. The archive database 184 may include an object table 188 having an entry (record) for each archived object providing information on the object and an expiration table 190 having one entry (record) for each initiated or expired retention period running with respect to one archived object.
The archive server 170 may be implemented as a server class machine, and the client systems 176a, 176b, 176c may comprise any computing device known in the art, such as a server class machine, mainframe, workstation, desktop computer, handheld computer, etc. The data archived from the client systems 176a, 176b, 176c may comprise data in a database, application program data, files in a file system, etc. The archival storage 174 may comprise any mass storage device known in the art, such one or more interconnected disk drives configured as a Redundant Array of Independent Disks (RAID), Just a Bunch of Disks (JBOD), Direct Access Storage Device (DASD), as a tape storage device, e.g., a tape library, or etc. The network 180 may comprise any interface between storage and a host known in the art, such as a network connection (e.g., Ethernet, wireless Ethernet, Fibre Channel, etc.) or any other network or storage transfer protocol known in the art.
In certain embodiments, different archival policies may be associated with the archived objects. The retention policy specifies a retention period during which the object must be maintained in archival storage 174. Following the duration of the retention period, the archived object is expired to allow the storage space to be reclaimed during a clean-up, reclamation or other space management operation. The object and the corresponding object entry in the object table 188 and any expiration entry for the object are removed. With certain archival policies, the retention period may commence immediately when adding the object to the archival storage and an entry to the archive database 184 providing information on the archived object.
An event based retention archival policy specifies that the retention period for the object does not commence until the occurrence of an event. Upon receiving a signal of the occurrence of the event, the archive program 182 would begin the retention period for the object having such event based retention archival policy. An event driven policy thus defers the beginning of the retention period counting until the occurrence of an event. For instance, employee information may be archived, but regulations may specify that after an employee leaves, information for that employee must be archived for a retention period of specified number of years. In such case, the event based retention policy may specify to commence the retention period upon being alerted of the event, which may comprise the separation of the employee from the organization. A retention period of zero for an event based retention policy would mean that the object expires immediately upon occurrence of the event. Further, an event based retention policy may specify a minimum retention period, in addition to the general retention period, such that the object cannot be expired before the minimum retention period expires, regardless of the event based retention period. Thus, if the time that has passed since the event signal occurs and the retention period time is less than the minimum retention period, then the object will not expire until the end of the minimum retention period. The minimum retention period may run from the time the object entry was added to the archive database 184 and storage 174, whereas the general event based retention period runs from when the event signal is received.
A deletion hold policy may be specified for an object to override the retention policy to prevent removal of an object even if the object would have expired according to the retention period defined in the archival policy for the object. Thus, if some event occurs that requires that the object remain archived regardless of any previously defined archival policy, then a deletion hold policy may be placed on that object to prevent expiration and removal of the archived object. For instance, if litigation commences against an employee that has departed, where an event based retention period is defined for the records of that employee to begin running when the employee departs (the event), then a deletion hold policy placed on the archived objects for that employee would prevent the expiration and removal of the archived objects for that employee regardless of the event based retention policy. The deletion hold applied to an archived object may subsequently be removed to allow that object to expire according to the archival policy defined for that object.
Further, a retention protection policy may be applied to the archive server 2 by setting the retention protection setting 186. Activating this setting 186 would cause the archive program 182 to inhibit or deny any request that seeks to remove or modify an archived object or remove any record in the archive database 184 for an archived object that has not expired according to the archive policy. A request to remove an archived object can be in the form of a request to remove that specific archived object or delete a volume or filespace including the specified archived object.
Further details of managing an event based retention policy are disclosed in the patent application entitled “Method, System, And Program For Retention Management And Protection Of Stored Objects”, having U.S. application Ser. No. 10/658,487, which application was incorporated herein by reference above.
Determinate and Indeterminate Retention of Files
FIGS. 7-11 provide an additional implementation for applying a retention policy to records or files that may alternatively be implemented by the archival filter 10 in FIG. 1 to apply a retention policy for records in the operating system 4.
FIG. 7 illustrates metadata 200 that may be associated with each record subject to a retention policy. Alternatively, the metadata may be associated with a subdirectory, i.e., retention directory, so that the retention policy specified by the retention policy applies to all files in that directory in the file system 6 (FIG. 1). The metadata 200 includes:

    
    
        Timestamp at Start of Retention Period 202: indicates a time a retention period policy begins to apply to a record.
        Timestamp at Deletion 204: indicates a time the record was deleted.
        Retention Period 206: indicates a time period during which the record is retained and not subject to removal, including shred, delete, purge. This retention period expires when the timestamp at the start of the retention period 202 plus the retention period 206 exceeds a current system timestamp.
        Audit Hold Flag 208: A flag indicating that any retention period is suspended and that the file cannot be removed due to an audit occurring.
        Legal Hold Flag 210: A flag indicating that any retention period is suspended and that the file cannot be removed due to instigation of legal or regulatory proceedings.
        Must Shred Flag 212: A flag indicating that when deleting the record, the system will automatically shred the record
        Permanent Hold Flag 214: A flag indicating that the record is in the permanent hold (PH) state and can never be deleted or shredded.
    
    


The metadata record 200 would further include an instance of multiple fields, shown as fields 216 through 226, for each event retention policy assigned to that record, such that a record may be associated with multiple event retention policies. The event metadata fields set for event included with the record metadata 200 include:

    
    
        Event Flag 216: A flag indicating whether an event based retention policy is associated with the record.
        Event Condition 218: The condition that must occur for the event to occur. The event may be specified by a database trigger. The event may comprise a condition occurring with respect to a person or organization related to the record. For instance, the event may comprise a user closing their account, separating from a company, etc., or performing any other action which would affect the status of one or more records related to their activity. The event flag 216 is set to “off” after the event condition occurs and is set to “on” before the event condition is satisfied.
        Post Event Retention Period 220: indicates a retention period that is effective upon the event condition being satisfied. For instance, the post event retention period 220 may be specified to prevent removal of the record for a number of years after the user closes their account. The post event retention period 220 expires when the timestamp at the time the event occurred 224 plus the post event retention period 220 exceeds the current system timestamp.
        Event Start Timestamp 222: indicates a time when the event flag 216 was set.
        Event Occurred Timestamp 224: indicates a time when the event signal is received indicating the event occurred. This signal may originate from a database program, such as a database trigger, from any application program or from user input action.
        Minimum Event Retention Period 226: indicates the minimum amount of time from the event start timestamp 222 that the record must be maintained. If the event occurs before the minimum event retention period has expired, then the record is maintained until the minimum event retention period has expired, even if the post event retention period 220 has expired.
    
    


FIG. 8 illustrates a state machine 250 that may be implemented in the archival filter 10 to determine the state of a record and whether the file may be deleted (D), shredded (S) or purged (P) depending on the retention policies indicated in the metadata 200 for the record. Following are possible states of a record as indicated in the state machine 250 (FIG. 7):

    
    
        E: a record whose metadata 200 has the event flag 216 set “on” indicating an event condition that is unsatisfied and, optionally, a post event retention period 220.
        RU: a record having an unexpired retention period 206 of a duration indicated by the retention period 206.
        RX: a record whose retention period 206 has expired, has no pending event condition, and is eligible for deletion. Further, if a file enters the system with no retention period, the file's initial state is the Rx state.
        EA: a record whose event flag 216 is set, indicating an event condition 218 is unsatisfied for the record, and the record audit hold flag is set indicating that the record is subject to an audit hold.
        EL: A record whose event flag 216 is set “on”, indicating that an event condition 218 is unsatisfied for the record, and that the record is subject to a legal hold.
        EAL: A record whose event flag 216 is set, indicating that an event condition 218 is unsatisfied for the record, and that the record is subject to both legal and audit holds.
        RUA: a record having an unexpired retention period 206 whose retention period 206 is suspended while the record is subject to an audit hold.
        RUL: a record having an unexpired retention period 206 whose retention period 206 is suspended while subject to a legal hold.
        RUAL: a record having an unexpired retention period 206 whose retention period 206 is suspended while subject to both audit and legal holds.
        RXA: a record whose retention period 206 is expired, i.e., is zero, has no associated event condition 218, but that cannot be removed due to an audit hold. Further, if a file enters the system with an audit hold and no retention period 206, then the file's initial state is the RXA state
        RXL: a record whose retention period 206 is expired, i.e., is zero, has no associated event condition 218, but that cannot be removed due to a legal hold. Further, if a file enters the system with a legal hold and no retention period 206, then the file's initial state is the RXL state
        RXAL: a record whose retention period is expired, i.e., is zero, has no associated event condition, but that cannot be removed due to audit and legal holds. Further, if a file enters the system with an audit and legal holds and no retention period, then the file's initial state is the RXAL state
        D: a record that is deleted.
        S: a record that is shredded, i.e., all the bits are overwritten and then deleted.
        P: a record whose metadata 200 is deleted. Further, the purge state is a final state.
        PH: a record subject to a permanent hold, where the record cannot expire, be deleted or have its retention policies ever altered. The permanent hold state is a final state.
    
    


The possible initial states include any of the above states except delete (D), shred (S) or purge (P). Further, all states are optional. Below are the state transitions that cause a transition from one state to another as shown in the state machine 250 (FIG. 8):

    
    
        A: audit hold is placed on the record.
         ̃A: audit hold is removed from a record
        L: legal hold is placed on the record.
         ̃L: legal hold is removed from a record
        E: an event condition 218 is associated with a record, a record previously not associated with an event condition 218 or whose event condition 218 was previously satisfied is now currently associated with an event condition or an additional event condition 218 is associated with a record with an existing event condition 218.
         ̃E: an event condition 218 associated with a record is satisfied.
        R: a retention period 206 is associated with a record.
         ̃R: a retention period 206 has expired with respect to a record.
        D: indicates receipt of a command to transition to a delete state where the record is deleted. Receiving a deletion transition at all states except the expired retention period state (RX) causes a transition back to the current state. Transition to the delete state is only allowed from the expired retention period state (RX).
        S: indicates receipt of a command to transition to a shred state where the record is shredded, i.e., all the bits are overwritten one or more times and then deleted. Receiving a shred transition at all states except the expired retention period state (RX) causes a transition back to the current state. Transition to the shred state is only allowed from the expired retention period state (RX).
        P: indicates receipt of a command to transition to a purge state where the metadata 200 (FIG. 7) for a record is deleted. Receiving a purge transition at all states except the delete (D) or shred (S) states causes a transition back to the current state. Transition to the purge state is only allowed after the record has been shredded or deleted.
        Pe: indicates a transition to the permanent hold state. A “Pe” transition from any but the purge (P) state goes to the permanent hold state (PH), and a “Pe” transition from the delete (D) or shred (S) state results in the metadata being kept permanently. A “Pe” transition from the purge (P) state returns to the purge (P) state.
    
    


FIG. 8 illustrates a state machine that shows how a record may transition from one state to another depending on the occurrence of one of the above described state transitions. In the described implementations, there are twelve transitions set forth above. In FIG. 8, all transitions from a state to a different state are shown, and all transitions from a state back to itself, i.e., no state change are implicit in that all loop-back transitions are assumed to be those of the twelve transitions not specifically shown. Further, the state machine shows that a permanent (Pe) transition from any state except the purge (P) state transitions to the permanent hold (PH) state.
FIGS. 9, 10, and 11 illustrate operations performed to implement the state machine 250 of FIG. 8. With respect to FIG. 9, upon receiving (at block 300) a command to delete or shred a record from the file system 6, the archival filter 10 (FIG. 1) determines (at block 302) whether the metadata 250 for the record has the audit hold flag 208, legal hold flag 210 or permanent hold flag 214 set “on”. If so, then the delete or shred request is denied (at block 304), which corresponds to receiving the delete (D) or shred (S) request at states EAL, EA, EL, RUAL, RUA, RUL, RXAL, RXA, RXL (FIG. 8). If (at block 302) all hold flags 208, 210, 214 are “off” and if (at block 306) the event flag is “on”, indicating that an event condition 210 associated with the record has not yet been satisfied, i.e., state “E”, then the request is denied (at block 304). If (at block 308) the retention period has not expired, i.e., the current system timestamp is less than the timestamp at the start of the retention period 202 plus the retention period 206, then the request is denied (at block 304), i.e., state RU. Otherwise, if the retention period has expired, i.e., the RX state, then the delete (D) or shred (S) operation is performed (at block 310), leading to the S or D state. The timestamp at deletion 204 is then set to the current system time. If the removal operation is a delete (D) and the must shred flag 212 is “on”, then the record would be shredded.
With the described implementations, every record has an explicit or implicit retention period, including: a retention period of zero where the record may be removed, i.e., in the RX states; an indefinite retention period such as those subject to a hold, e.g., an audit (A) and/or legal (L) hold; a determinate retention period such as for a specified period of time, i.e., one of the RU states; or a record subject to retention until the occurrence of an event, i.e., one of the E states. If a record subject to an event condition 210 has an event retention period 214 of zero, then upon the occurrence of the condition the retention period would end and the record may be subject to removal.
FIG. 10 illustrates operations performed by archival filter 10 or some other component, such as a database program, to handle the occurrence of an event condition, such as an employee leaving, account being closed. This may occur asynchronously with respect to users attempting to delete files or may occur when a delete request is received before the event flag 216 is checked (at block 306, in FIG. 9). Upon detecting (at block 350) the occurrence of an event condition 218 for a record, the event occurred timestamp field 224 is set (at block 352) to the current system timestamp. The retention period 206 is set (at block 354) to the post event retention period 220 to prevent removal of the file until the post event retention period 220 has expired. If (at block 356) the event retention policy for which the signal was received has not applied for the minimum event retention period 226, i.e., the current system time is not greater than the event start timestamp 222 plus the minimum event retention period 226, then action taken on the event occurrence is delayed (at block 358) until the current system time is equal to the event start timestamp 222 plus the minimum event retention period 226. From the yes branch of block 356 or block 358, control proceeds to block 360 where the event flag 216 is set (at block 360) “off”.
FIG. 11 illustrates operations performed by the archival filter 10 to process a request to purge the metadata 200 for a record. Upon receiving (at block 370) the purge request, if (at block 372) the timestamp at deletion 204 is set to a non-null timestamp value, which would occur when the record is shredded or deleted, then the metadata 200 associated with the record is deleted; otherwise, the purge request is denied.
Described embodiments provide techniques for managing files subject to a retention policy that are not to be removed for certain organizational reasons, such as until a certain event occurs, if the record is related to activity subject to legal and/or an audit, etc. This allows organizations or individuals to prevent inadvertent or malevolent deletion of records during the retention period.
ADDITIONAL EMBODIMENT DETAILS
The retention policy management system described herein may be implemented as a method, apparatus or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” as used herein refers to code or logic implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.) or a computer readable medium, such as magnetic storage medium (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.). Code in the computer readable medium is accessed and executed by a processor. The code in which preferred embodiments are implemented may further be accessible through a transmission media or from a file server over a network. In such cases, the article of manufacture in which the code is implemented may comprise a transmission media, such as a network transmission line, wireless transmission media, signals propagating through space, radio waves, infrared signals, etc. Thus, the “article of manufacture” may comprise the medium in which the code is embodied. Additionally, the “article of manufacture” may comprise a combination of hardware and software components in which the code is embodied, processed, and executed. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present invention, and that the article of manufacture may comprise any information bearing medium known in the art.
In certain described implementations, the user associates a retention policy with a directory by indicating a retention policy code in the name of the directory to apply to all files included in that directory. In alternative implementations, the user may associate a retention policy with a directory in a manner other than coding the pathname of the directory. For instance, the user may associate retention policies with the attributes defined for a directory of the file system, which may or may not be indicated in the name of the directory or graphical rendering of the directory in a graphical user interface providing a rendering of the hierarchical file system. In certain operating systems, such as the MICROSOFT WINDOWS operating system, the attributes that may be assigned to a directory are accessed by right clicking a mouse button over the name of the directory displayed in a user interface window to display a menu, and then selecting the properties option displayed in the menu. (Microsoft and Windows are registered trademarks of Microsoft Corporation).
In certain described implementations, the archival filter 10 is shown as a separate program component. The archival filter 10 may be installed separately from the file system 6, such as a separately installed application program that runs when the operating system 4 and file system 6 are initialized and screens files the user is attempting to erase or move. Alternatively, the functionality of the archival filter may be incorporated directly in the operating system and be made available as a feature of the file system installed with the operating system. The archival filter 10 may execute in the kernel of the operating system or at different priority levels.
In described implementations, a retention policy associated with a directory applied to all files within that directory, including files in subdirectories of the directory associated with the retention policy. In further implementations, certain subdirectories within the retention policy directory may include files not subject to the retention policy, such as the case with a hold directory grouping files that are retained indefinitely, irrespective of any retention policy associated with a directory in which the hold directory is included.
In described implementations, a non-re-writable and non-erasable type restriction policy is applied to files in a directory associated with the retention policy for the time period specified by the retention policy. In alternative implementation, different retention restrictions may be applied to files subject to the retention policy.
In described implementations, the coding of the retention policy in the directory pathname comprised a description of the retention policy. In alternative implementations, the coding of the retention policy in the pathname may comprise a code that is not descriptive of the retention policy. For instance, the pathname may be coded with “Retain3Years”, which is a description of the retention policy, or a non-descriptive code, e.g., “X11”, which may not provide any description of the actual retention policy.
FIGS. 3, 4, 5, 9, 10, and 11 describe specific operations occurring in a particular order. In alternative implementations, certain operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described implementations. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units.
FIG. 7 illustrates information that may be included with the metadata 200 for a record. Additional or different metadata information may be used to manage the retention policy and allow for event driven and other policy related holds, such as legal and audits. Further, additional organizationally defined retention holds may be provided other than audit and litigation.
FIG. 8 illustrates an implementation of a state machine including defined possible states for a record subject to a retention policy and transitions between states. In alternative implementations, additional states may be provided and alternative and different transitions may be used to provide different transitions among states than shown in the state machine of FIG. 8.
FIG. 12 illustrates one implementation of a computer architecture 400 of the host system 2 shown in FIG. 1. The architecture 400 may include a processor 402 (e.g., a microprocessor), a memory 404 (e.g., a volatile memory device), and storage 406 (e.g., a non-volatile storage, such as magnetic disk drives, optical disk drives, a tape drive, etc.). The storage 406 may comprise an internal storage device or an attached or network accessible storage. Programs in the storage 406 are loaded into the memory 404 and executed by the processor 402 in a manner known in the art. The architecture further includes a network card 408 to enable communication with a network. An input device 410 is used to provide user input to the processor 402, and may include a keyboard, mouse, pen-stylus, microphone, touch sensitive display screen, or any other activation or input mechanism known in the art. An output device 412 is capable of rendering information transmitted from the processor 402, or other component, such as a display monitor, printer, storage, etc.
The foregoing description of the implementations has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many implementations of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

## Claims

1. A computer implemented method, comprising:
receiving a request by a computer to remove a record stored in a storage server;
determining whether a state associated with the record includes at least one hold state;
determining whether the state associated with the record includes at least one retention period that has not expired; and
denying the request to remove the record in response to determining that the state associated with the record includes at least one state comprising: the at least one hold state and/or the at least one retention period that has not expired.

2. The method of claim 1, wherein the at least one hold state includes at least one of an audit state, a legal state, and a permanent hold state, wherein the audit state is applied if the record is involved in an organizational audit, wherein the legal state is applied if the record is involved in a regulatory action, and wherein the permanent hold state applies once specified.

3. The method of claim 1, wherein at least one state capable of being associated with the record includes both the at least one retention period and the at least one hold state.

4. The method of claim 1, further comprising:
determining whether the state associated with the record includes an event state specifying an event condition, wherein the request is denied if the state associated with the record includes the event state whose event condition has not been satisfied.

5. The method of claim 4, wherein at least one state includes at least two of the states comprising: the event state, the at least one hold state, and the at least one retention period.

6. The method of claim 5, further comprising:
receiving indication that the event condition for the event state associated with the record is satisfied; and
initiating a retention period for the record associated with the event state in response to detecting the satisfaction of the event condition, wherein the record is associated with the at least one state including the retention period in response to satisfying the event condition.

7. The method of claim 1, further comprising:
receiving a request to purge metadata associated with one record;
determining whether the record subject to the requested purge is associated with one state where the record was removed; and
allowing the purging of the metadata if the record subject to the purge is associated with one state where the record was removed.

8. A data storage system in communication with a data storage device, comprising:
a processor;
a computer readable storage medium tangibly embodying code executed by the processor to cause operations to be performed, the operations comprising:
receiving a request to remove one of a plurality of records from the data storage device;
determining whether a state associated with the record includes at least one hold state;
determining whether the state associated with the record includes at least one retention period that has not expired; and
denying the request to remove the record in response to determining that the state associated with the record includes at least one of the states comprising: the at least one hold state and the at least one retention period that has not expired.

9. The system of claim 8, wherein the at least one hold state includes at least one of an audit state, a legal state, and a permanent hold state, wherein the audit state is applied if the record is involved in an organizational audit, wherein the legal state is applied if the record is involved in a regulatory action, and wherein the permanent hold state applies once specified.

10. The system of claim 8, wherein at least one state capable of being associated with the record includes both the at least one retention period and at least one hold state.

11. The system of claim 8, wherein the operations further comprise:
determining whether the state associated with the record includes an event state specifying an event condition, wherein the request is denied if the state associated with the record includes the event state whose event condition has not been satisfied.

12. The system of claim 11, wherein at least one state includes at least two of the states comprising: the event state, the at least one hold state, and the at least one retention period.

13. The system of claim 12, wherein the operations further comprise:
receiving indication that the event condition for the event state associated with the record is satisfied; and
initiating a retention period for the record associated with the event state in response to detecting the satisfaction of the event condition, wherein the record is associated with one state including the retention period in response to satisfying the event condition.

14. An article of manufacture comprising a tangible medium tangibly embodying code executable by a computer and in communication with a data storage device to cause operations to be performed by a computer with respect to managing a retention policy with respect to records, the operations comprising:
receiving a request to remove one record from the data storage device;
determining whether a state associated with the record includes at least one hold state;
determining whether the state associated with the record includes at least one retention period that has not expired; and
denying the request to remove the record in response to determining that the state associated with the record includes at least one state comprising: the at least one hold state and the at least one retention period that has not expired.

15. The article of manufacture of claim 14, wherein the at least one hold state includes at least one of an audit state, a legal state, and a permanent hold state, wherein the audit state is applied if the record is involved in an organizational audit, wherein the legal state is applied if the record is involved in a regulatory action, and wherein the permanent hold state applies once specified.

16. The article of manufacture of claim 14, wherein at least one state capable of being associated with the record includes both the at least one retention period and at least one hold state.

17. The article of manufacture of claim 14, wherein the operations further comprise:
determining whether the state associated with the record includes an event state specifying an event condition, wherein the request is denied if the state associated with the record includes the event state whose event condition has not been satisfied.

18. The article of manufacture of claim 17, wherein at least one state includes at least two states comprising: the event state, at least one hold state, and the at least one retention period.

19. The article of manufacture of claim 18, wherein the operations further comprise:
receiving indication that the event condition for the event state associated with the record is satisfied; and
initiating a retention period for the record associated with the event state in response to detecting the satisfaction of the event condition, wherein the record is associated with one state including the retention period in response to satisfying the event condition.

20. The article of manufacture of claim 14, wherein the operations further comprise:
receiving a request to purge metadata associated with one record;
determining whether the record subject to the requested purge is associated with one state where the record was removed; and
allowing the purging of the metadata if the record subject to the purge is associated with one state including the removal of the record.