Abstract:
A removable data storage cartridge has a shock sense indicator attached to its housing. The indicator includes a sensing structure that reacts to a shock event over a specified threshold. The invention indicates a physical shock event upon appropriate inquiry by the reader mechanism. Upon detecting that a shocked data storage cartridge has been loaded into a data storage library, the library and/or data storage drive alerts the operator and/or system administrator and moves the shocked cartridge to a quarantine pool to prevent damage to the data storage drive.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to data storage systems, and more particularly, to a method and apparatus for controlling load operations of a data storage cartridge that has been subjected to a shock event. 
     2. Description of the Related Art 
     This invention is directed to the providing of a method and apparatus for controlling load operations of a data storage cartridge that has been subjected to a shock event. One of the problems facing organizations that use magnetic tape media to protect their data is what can happen when a data storage cartridge is dropped. When a data cartridge sustains g-forces in excess of 40 G it is much more likely to experience failure during restore operations. According to those knowledgeable in the art, up to 35% of all restore failures can be traced to dropped or damaged data cartridges. 
     Dropped data cartridges can experience damage in one of two ways. One way that dropped data cartridges may experience significant damage to the tape edge is via impact to the external case, which impact is transmitted to the reel and subsequently to the tape. Damage to the tape edge can render read or write operations on the tracks in that damaged location unreliable or impossible. Dropped data cartridges may continue to operate for a period of time after being dropped, since the tape may not write or read data in the outer tracks due to low utilization. This can lead to a false sense of reliability by backup administrators, since the cartridge may appear to operate normally after being dropped, when in reality it has been damaged. 
     Another way that dropped data cartridges may experience significant damage is by displacement of the leader pin as a result of the cartridge experiencing an excessive g-force during a drop event. A sudden deceleration may deform the plastic cartridge enclosure and slot where the leader pin is normally held, thereby causing the leader pin to move out of reference position. If the leader pin moves out of reference position, the data storage drive may not be able to successfully load the cartridge. 
     In certain circumstances, a malfunction can occur during the load operation of a dropped cartridge, which may render both the cartridge and the data storage drive inoperable. Many data storage drive manufacturers will void the drive warranty if a defective cartridge is loaded into the drive and a malfunction results. Data stored on a cartridge that has malfunctioned in this way may become irretrievable. 
     Further compounding the issue is failure by backup operators and administrators to take appropriate action when a tape cartridge is dropped. Factors contributing to the problem are: (1) failure of operators and backup administrators to understand the negative effects of excessive g-forces on dropped media; (2) Failures of operators and backup administrators to report dropped cartridges to management for fear of reprimand; and (3) failure to remove dropped media from active storage pools. 
     Depending on the value of the data stored on the cartridge and the severity of damage, dropped media may be duplicated, but dropped cartridges should be treated as read only. Ideally, dropped cartridges should be taken out of service as soon as possible to avoid any potential negative impact on data storage drives and to preserve library performance during backup and restore operations. 
     The impact of dropped data cartridges is two-fold. First, dropped data cartridges are more likely to fail or cause errors during restore operations and either of these events can delay system recovery by negatively impacting the Recovery Time Objective (RTO), since the administrator will likely need to abort the current restore operation. Restoring the data from the next previous backup also significantly delays system availability. (Offsite media will also significantly delay the recovery process.) Secondly, irretrievable data from dropped cartridges may negatively impact the Recovery Point Objective (RPO), since the system may not be able to be restored to the desired state. As a consequence, data may be lost. Reverting to the previous full backup, which is usually at least 24 hours, or 7 or 14 days old will likely inhibit achieving the desired RPO. 
     If backup administrators have knowledge of cartridge mishandling, they can preemptively adjust backup processes and procedures to maintain acceptable RTO and RPO in the event of data loss. Loading dropped cartridges into drives may result in a drive becoming inoperable and being removed from service. Repair requires removal of the drive (with the cartridge partially loaded) from the library and the return of the drive to the manufacturer for extraction of the data cartridge and repair of the drive. Sometimes this incurs great cost to the customer, as this type of repair is not usually covered under warranty. Removing data storage drives from service may also negatively impact an organization&#39;s ability to adequately protect its data or perform restore operations until the asset is returned to service. 
     While it is apparent that the problems associated with a storage cartridge that has been subjected to a shock event have been recognized, no solution has been found. It is thus readily apparent that the long-felt need continues to exist for a method and apparatus for controlling load operations associated with data storage cartridges that have been subjected to a shock event. 
     SUMMARY OF THE INVENTION 
     In accordance with this invention an apparatus for controlling load operations of a data storage cartridge that has been subjected to a shock event is provided, the apparatus being a removable data storage cartridge device having a housing, a tape medium contained in the housing, and a passive shock detection sensor secured to the housing that records shock to the cartridge by indicating a machine-readable shocked status. The shock is a deceleration of the data storage cartridge at a predetermined threshold, with the predetermined threshold being at least 390 m/sec2 or 40 G. 
     Preferably, the shock detection sensor is integrated in a barcode label attached to the cartridge. Preferably, the barcode label has a barcode data string consisting of a start character, a plurality of alphanumeric characters, an optional checksum character, and a stop character. In one embodiment of the invention, each of the start and stop characters are preceded and followed by quiet zones. In one embodiment, a portion of the label indicates if a shock event has occurred. Additionally, the existence of a shock event of a predetermined threshold can be visually displayed on the cartridge. 
     There is also disclosed a tape library comprising a chassis containing any number of drive or media frames, slots that store removable data storage cartridges, data storage drives that read and write data storage cartridges, a transporter mechanism that imports, exports and moves data storage cartridges between slots, from a slot to a drive, or from a drive to a slot, a network connection to communicate with backup software applications, a front panel having a display and means for issuing commands and receiving feedback from the tape library, and a controller, with the controller including an operating system that manages the tape library, and with the operating system containing specialized add-on code to instruct the transporter mechanism to detect shocked cartridge status via disrupted barcode. 
     The tape library has an entry/exit pool and a tape library barcode reader. The tape library has firmware and/or an operating system that can be altered to prevent loading of a damaged cartridge into a data storage drive mechanism. The tape library controller alerts the operator and/or administrator of the tape library as to the presence of a shocked cartridge via the tape library front panel, and/or the backup software administration, and/or the operator console(s). 
     There is also disclosed a method for controlling data storage cartridge load operations in a data storage system comprising the steps of querying the shock status of a data cartridge when the cartridge is imported into a tape library, moving a shocked cartridge to dedicated slots in the tape library should the query of the cartridge indicate a shocked status, the dedicated slots defining the quarantine pool, and inhibiting the movement of any cartridges in the quarantine pool, the tape library being configurable to allow export from the library or to allow an operator override to continue load operations. 
     The method also includes the step of sending SCSI commands to the backup system indicating the cartridge location in the library and the disabled status of the cartridge. The method also includes the step of sending XML formatted data via a library controller network interface indicating the cartridge location in the library and the disabled status of the cartridge. 
     The primary objective of this invention is to passively and unobtrusively detect shock events of a predetermined threshold for industry standard or proprietary cartridge formats. 
     Another objective is to provide a data storage cartridge that can record a shock event so that the existence of the shock event can be ascertained by being machine readable using the type of existing barcode reading equipment that is present in modern tape libraries, with no change to hardware and only minor changes to software and/or firmware potentially required. 
     Still another objective is to provide existing tape libraries with a method that can be integrated into existing tape libraries, with only minor changes to software and/or firmware. An important aspect of this objective is that the method would physically isolate shocked cartridges and prevent the loading of shocked cartridges into drives. 
     Yet another objective is to provide a method to prevent loading of shocked cartridges into drives via automated mechanisms and to alert storage administrators of the presence of a shocked cartridge either indirectly (through operator intervention by the removing of the shocked cartridge(s) from the tape library) or directly (by network communication with commercially available backup software packages) so that: (1) the data on a disk (or on a source tape, in the case of a cartridge duplication operation) may be protected using an alternate cartridge and (2) the shocked cartridge may be removed from service. 
     Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a data storage drive made in accordance with the present invention. 
         FIG. 2  is a perspective view of a removable data storage cartridge made in accordance with the present invention. 
         FIG. 3  discloses one embodiment of a shock sense indicator in a normal state integrated within a cartridge label for use on the removable data storage cartridge as shown in  FIG. 2 . 
         FIG. 4  discloses the embodiment of a shock sense indicator as shown in  FIG. 3 , but in a shocked state. 
         FIG. 5  discloses a schematic diagram of one embodiment of a shock sensing structure that may be integrated into the cartridge label as shown in  FIG. 2 . 
         FIG. 6  discloses a schematic diagram illustrating the various components of a modified label with the shock sensing structure embedded in a further embodiment of the present invention. 
         FIG. 7  is a functional block diagram of a data storage system illustrating components used in operation of a method in accordance with a further embodiment of the present invention. 
         FIG. 8  is a flow chart illustrating the method for controlling cartridge load operations in a data storage system in accordance with the embodiment of the method of the present invention. 
     
    
    
     In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Having reference to the drawings, attention is directed first to  FIG. 1  which discloses a data storage drive  101  made in accordance with the present invention. The current version of the data storage drive  101  is similar to prior art data storage drives and has an opening  102  to permit loading of a data storage cartridge. 
     The data storage cartridge associated with the invention is disclosed in  FIG. 2  and is designated by the numeral  103 . The cartridge  103  has a designated label area  105  inside of which the cartridge label of the type used on such data storage cartridges must fit. The data storage cartridge  103  may further be comprised of an access door  104  that can open and close in order to allow a data storage drive to access the leader pin and extract the tape within for reading or writing in the manner known in the prior art. In accordance with the present description of the data storage device  103  on which the device label may reside, a passive shock detection sensor may be enclosed within, on, or around the data storage device label. A passive shock detection sensor is characterized as being a mechanical device and does not require application, transmission or storage of electrical current to detect, record or indicate that a shock event has occurred. As such, the sensor is electrically non-invasive and does not require addition of electro-mechanical devices, batteries, circuits or electrical current to be applied, stored, or transmitted inside the cartridge housing. 
       FIG. 3  discloses a view of a data storage cartridge label  201  in a normal state, while  FIG. 4  discloses a view of a data storage cartridge label in a shocked state  209 . The label  201  is comprised of a customer configurable label area  203 , a machine-readable barcode area  207  and an area for the viewable portion of shock sensing structure  205 .  FIG. 4  discloses the data storage cartridge label  201  in a shocked state, with the shocked state being shown by the presence of black bar codes  211  on the front of the cartridge label  201  in the area for the viewable portion of shock sensing structure  205 . 
       FIG. 5  is a schematic of an embodiment of the shock sensing structure  300  of the present invention. In this embodiment, a main reservoir  300  of black ink  301  is maintained under pressure and restrained by a barrier  302  that is manufactured to fracture at a specified deceleration threshold. Upon fracture, the barrier  302  will release the ink  301  from the main reservoir  300  into the vertical transfer tube  303  and then flow into the intermediate reservoir  304 . As the intermediate reservoir  304  is filled, ink will eventually flow into horizontal transfer tubes  305  and  307  and finally enter the outer reservoirs  306  and  308  respectively. The vertical transfer tube  303 , intermediate reservoir  304 , left and right outer reservoirs  306  and  308  respectively, and horizontal transfer tubes  305  and  307  are manufactured under vacuum to enable quick and even distribution of the ink  301  or other colored liquid from main reservoir  300  upon fracture of barrier  302 . 
       FIG. 6  is a schematic diagram illustrating the construction of a tape label with an embodiment of the present invention  300 . The tape label will be composed starting from back to front first of a double-sided adhesive  401 , which is adhered to a white paper backing material  402 . The present invention  403  will be positioned precisely within the label area per customer specification and covered with a white label  404  with three clear apertures to allow the reservoirs  306 ,  304 ,  308  to remain visible. Finally, a clear protective coating with a matte finish and single sided adhesive  405  will be applied over the label to secure the protective coating  404  and to provide a substrate suitable for printing color labels and barcodes. 
       FIG. 7  is a generalized block diagram  500  of a tape library  501 . The data storage device shown in  FIG. 1  is housed in the tape library  501  of  FIG. 7 . It is comprised of a chassis or frame either rack mounted or free standing and contain any number of drive or media frames. The present example  500  indicates a single frame library  501  for illustration purposes. A tape library  501  by definition will contain slots  503  to hold cartridges  103 , an entry/exit (E/E) port(s)  517  to permit import and export of data storage cartridges  103  and drive bays  547  for installation of a data storage drive(s)  101  or  521  and  525  for reading and writing data cartridges  103 . A library  501  can contain as few as 24 slots  503  and up to 30,000 slots or more. 
     Slots that are licensed to store data storage cartridges  103  are usually allocated to various storage pools  505 . Slots that are present in the library, but not licensed are normally unavailable to the library and not visible to backup applications and are referred to as unassigned slots  509 . In an embodiment of the present invention a new type of slot is introduced called a quarantine slot  507 . Quarantine slots  507  will be used to temporarily store shocked cartridges  103  until they are removed from the library  501  or an operator or administrator override  613  is issued and released to storage slots  505  for normal operations which may include eventual loading into data storage drives  521  and/or  525 . 
     Additionally, a transporter or robot mechanism  511  will be present to import, export and move data storage cartridges  103  from slot  503  to slot, slot to drive  521  or  525  (load) and drive to slot (unload). The transporter mechanism  511  may also be integrated with a picker mechanism  515  for physically manipulating cartridges  103  and an optical barcode reader  513  to read barcodes  207  on tape labels (of the type disclosed in  FIG. 3  as  201  or in  FIG. 4  as  209 ) and can preferably also read modified barcode labels (of the type disclosed in  FIG. 4  as  211 ) with an integrated shock sensor  300  as shown in an embodiment of the present invention. The transporter mechanism  511  will move about the x, y and z-axis  519  of the tape library  501  by various mechanisms to accomplish cartridge  103  moves, load and unload operations from data storage drives  521  or  525 . 
     The library control module  529  controls all library  501  operations and management functions and is composed of several major components, including the library controller  531 , remote library controller  533 , robotics control module  537 , Non-Volatile Random-Access Memory (NVRAM)  539  and an operating system  535 . The operating system  535  links and controls all major components of the tape library  501  and is usually stored in NVRAM  539 . The operating system  535  is often upgradeable and in an embodiment of the present invention can be modified to introduce the concept of quarantine slots  507 , subroutines  600  and instruction set modifications to the bar code reader to permit the present invention  200  to be utilized. The operating system  535  is usually executed by a processor on the Library controller  531  for local operations or on the remote library controller  533  in the event of remote operation via remote network by Ethernet port  541 . The operating system  535  will also govern the Robotics Control Module  537 , which controls all aspects of the transporter  511  movement and function. 
     Several interfaces  541 ,  543  and  545  will also be present on the tape library  501  and are usually part of the library control module  529  to allow for management and communication such as an Ethernet port  541 , serial port  543  and/or Universal Serial Bus (USB) port  545 . The library control module  529  and its resident operating system  535  manage the Ethernet  541 , serial port  543  and USB interfaces  545  in the present example  500 . 
     Data storage drives  521  and  525  may contain multiple storage specific interfaces  549 ,  551  and  553 ,  555  such as SCSI, iSCSI or Fibre Channel for direct connection to hosts, backup servers, media servers or via indirect connection to similar devices via Storage Area Network (SAN) or Local Area Network (LAN) switches. Drives  521  and  525  may contain a drive control module  523  and  527 , which may be integrated in an optional drive sled to control drive  521  and  525  operations and/or management functions via commands from the library control module  529 . Modern tape libraries  501  can have anywhere from one to 120 data storage drives  101  with future designs projected to support upwards of four hundred drives. Also part of the tape library are power control module  560  with its power supplies  561 ,  562  respectively, and fan control module  570  with its fans  571 ,  572 . 
       FIG. 6  is a flow chart description  600  of one embodiment of a method for the load operation that a tape library  501  or similar device could perform when a data storage cartridge  103  such as in  FIG. 1  is inserted into a device as described in  FIG. 5 . When the data storage cartridge is loaded as described by block  601  the Shock Sensor can be read as per block  603  and a decision can then be made based upon that reading, as seen in block  605 . Based on that decision, the tape library  501  can possibly perform two different actions. If the Shock Sensor Status is negative  205  in whether it was subjected to significant shock or not, then the tape library can continue to perform the normal course of actions described by block  607  as per the instruction set of the tape library  501  or similar device. If the shock sensor has been subjected to a shock event in excess of a predetermined threshold that would result in the reading of the Shock Sensor being positive  211 , then the tape library  501  could display an error message on monitor  557  to alert an administrator or designated recipient, as indicated by block  609 . Once the alert has been logged, the tape library  501  may then move the shocked data storage device  103  to designated Quarantine Slots  507  as shown in block  611 . The administrative user of the tape library  501  could then be given the option to remove the shocked data storage device  103  from the tape library  501  as indicated in block  613 . If the administrative user would decide to remove the shocked data storage device  103 , then it would be removed as indicated in block  615 . However, if the administrative user issues an override and decides to leave the shocked data storage device  103  in the tape library  501 , then the tape library  501  would continue the load operation as indicated by block  607 . 
     While the form of apparatus and method herein described constitute a preferred embodiment of the apparatus and method of the present invention, it is to be understood that the invention is not limited to this precise form of apparatus or method of using the apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.