Patent Application
20060092544
Tape drives are widely used for storing information in digital form. These tape drives may be utilized as part of a tape subsystem, which may include a storage subsystem controller for controlling one or more tape drives contained within the storage subsystem and for controlling other components of the storage subsystem, such as the tape picker, which is used to select and load tape cartridges into the tape drives. The storage subsystem may be coupled to a host system b which transmits I/O requests to the storage subsystem via a host/storage connection.
Each tape drive reads and writes data to a tape medium contained within a data storage tape device, which can be, for example, a magnetic tape cartridge 100, shown in
While it may be advantageous for the data storage tape device to be removable and portable, this portability also increases the likelihood that the data storage tape device will experience some sort of shock event caused by mishandling. In some cases, the damage caused by the shock event is undetectable upon a visual inspection of the data storage tape device. For example, dropping a tape cartridge such that the cartridge receives a 45-50 g shock along the reel axis may cause damage to the edge of the tape medium. If the damaged data storage tape device is loaded into a tape drive, the damage may only become apparent when the tape drive is unable to properly read data from the data storage tape device. In addition, merely attempting to load the damaged data storage tape device into the tape drive and read data from the device may exacerbate the damage to the tape medium.
When the damage to the tape device is not perceivable by the human operator, the operator may not be able to diagnose the errors caused when attempting to read or write data to the tape device. Therefore, it can be difficult to diagnose whether the errors are being caused by the tape device or the tape drive. Even when a specialized failure analysis engineer inspects the tape device, the cause of the damage may not be readily apparent.
In accordance with embodiments of the present invention, a data storage tape device is provided, comprising: a housing; a tape medium contained in the housing; and a human-perceivable shock indicator having a default status and a disrupted status, the shock indicator switching from the default status to the disrupted status in response to a shock event of at least a predetermined threshold such that the disrupted status of the shock indicator is human-perceivable.
In accordance with other embodiments of the present invention, a method of determining a status of a data storage tape device is provided, comprising: receiving a data storage tape device comprising a housing, a tape medium contained in the housing, and a human-perceivable shock indicator having a default status and a disrupted status, the shock indicator switching from the default status to the disrupted status in response to a shock event of at least a predetermined threshold such that the disrupted status of the shock indicator is human-perceivable; and perceiving a status of the shock indicator using an unaided human sense.
In accordance with other embodiments of the present invention, a data storage tape device is provided, comprising: a housing; a tape medium contained in the housing; and a shock indication means for indicating in a human-perceivable fashion a switch from a default status to a disrupted status in response to a shock event of at least a predetermined threshold.
Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features in accordance with embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto.
In the following description, reference is made to the accompanying drawings which illustrate several embodiments of the present invention. It is understood that other embodiments may be utilized and mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description is not to be taken in a limiting sense, and the scope of the embodiments of the present invention is defined only by the claims of the issued patent.
In accordance with embodiments of the present invention, a shock indicator may be provided on a data storage tape device to assist users in detecting when the data storage tape device has been subjected to a shock event that is beyond an intended design threshold, thereby posing a risk of data loss. This detection may be performed using only human senses, without the use of a reader mechanism or other detecting device, thereby dramatically increasing the ease and speed with which the shock event can be detected. A human-perceivable indicator is a device that indicates two or more different states in a way that is perceivable by a human without the assistance of amplification, magnification, or other sensing device. In some cases, the human-perceivable indicator may be one that indicates its current state using a visible indicator, such as a color change. In other cases, the human-perceivable indicator may indicate its current state by providing some sort of audible feedback. In other cases, the human-perceivable indicator may indicate its current state by providing some sort of tactile feedback.
The shock indicator 210 is configured to switch from the default state to the disrupted state in response to being subjected to a shock event. In some embodiments, the shock indicator 210 is configured to respond to shock events which occur in a particular direction and of a predetermined magnitude. For example, the shock indicator 210 may be configured to respond to an acceleration or deceleration of at least 45 g along the reel axis (i.e., the axis of rotation of the cartridge reel contained in the tape cartridge 200). If the shock indicator 210 experiences such an acceleration or deceleration, the shock indicator 210 will switch to the disrupted state shown in
In the embodiment shown in
The shock indicator 210 in
In other embodiments, however, the indicator may be configured to be sensitive to shock events in one or more other directions. For example, a tape cartridge may include a shock indicator 210 oriented in another direction or multiple shock indicators 210 oriented in a plurality of directions, such that the shock events in other directions can cause the shock indicator(s) 210 to change state. This may be preferable when the data storage tape device and/or the tape media is sensitive to damage caused by shock events occurring in directions other than the reel axis. In some embodiments, it may be desirable to have a first shock indicator having a first shock threshold for detecting shock events in a first direction, and a second shock indicator having a second shock threshold higher than the first shock threshold for detecting shock events in a second direction non-parallel with the first direction. Thus, the first shock indicator can be positioned to detect shock events occurring along the reel axis and the second shock indicator can be positioned to detect shock events orthogonal to the reel axis. This second shock indicator may have a significantly higher shock threshold corresponding to the tape cartridge's greater tolerance for shock events orthogonal to the reel axis.
In accordance with other embodiments, a data storage tape device includes a shock indicator that provides a status indication using an audible indicator. This audible indicator can be, for example, a rattling sound caused by a body that is dislodged when the data storage tape device is subjected to a shock event of a predetermined threshold.
The chamber 412 may be sufficiently enclosed such that when the ball bearing 430 is dislodged, the ball bearing 430 cannot exit out of the chamber 412 and interfere with the operation of the data storage tape device or the tape drive in which the tape device is loaded. This chamber 412 may be integrally formed with the housing for the tape device, such as during the molding process, or may be added as a separate component either to the inside or the outside of housing.
In these embodiments, if a force F1 is applied to the shock indicator, the ball and spring will react. If the force is of sufficiently high amplitude and duration, the ball bearing will go into resonance with the spring and will be released from the support flange or the other spring. The ball bearing will then be free to rattle about within the chamber. In addition, the shock indicators 410, 510 may be sensitive to forces in the transverse direction, i.e., force F2 perpendicular to the axis of compression of the springs 420, 520. In this case, if the shock indicator experiences a force F2 sufficiently high as to exceed the capture force of the spring(s), then the ball will be released.
In accordance with various embodiments, it may be desirable to use shock indicators that are responsive to different types of shock events. For example, in some cases, it may be desirable to have a shock indicator that will switch from the default status to the disrupted status upon being subjected to a shock event that exceeds a predetermined maximum acceptable acceleration. In other instances, it may be desirable for the shock indicator to be responsive to a combination of both the magnitude and the duration of the acceleration.
In some embodiments, it may be desirable to modify a shock indicator to be responsive to shock events depending on the nature of the tape device. This modification may include changing one or more of the spring tension, the spring constant, and the mass of the dislodgeable body to tune the threshold curve to the desired shape, depending on the design and intended usage of the tape device. For example, if the tape device can withstand larger magnitude shock events, a greater spring tension may be used so that the ball bearing is only dislodged upon subjection to the threshold shock event. The appropriate design for the spring and the dislodgeable body may be obtained using empirical tests to determine the optimal characteristics such that the desired shock threshold limit is provided.
In accordance with other aspects of the present invention, the shock indicator 710 may be resettable to the default state after having experienced a disrupting shock event. As can be seen in
In other embodiments, a resettable shock indicator 710 may be provided using different configurations. For example, in place of the access opening 716, a button, flange, or other movable member may be provided on the shock indicator 710 in a location accessible by a user. This movable member may be coupled to a resetting member that would contact the body 730 inside the chamber 712. Thus, when a user applies a force onto the button, flange, or other movable member on the outside of the shock indicator 710, the member will transfer this force onto the body 730, causing the body 730 to be pushed back into the default position.
In other embodiments, the resettable shock indicator may be configured such that the shock indicator may be reset by the factory or other trained technician, but not by a casual end user. This may be accomplished, for example, by covering the access opening 716 or by positioning the shock indicator 710 such that the access opening 716 can only be accessed by opening up the cartridge housing. This may help to prevent untrained users from resetting the shock indicator without performing a complete diagnostic check on the cartridge to determine whether any damage has occurred.
In accordance with other aspects of the present invention, the shock indicator 710 may provide an optical indication of the indicator state. As can be seen in
This arrangement may enable a shock indicator 710 to provide an audible indication of its disrupted state, thereby facilitating rapid detection by the user of potential damage caused by a shock event. In addition, the shock indicator 710 may provide an optical indication of its disrupted state, thereby enabling the tape drive 800 to also detect the state of the shock indicator 710. When the tape drive 800 detects that the shock indicator 710 is in the disrupted state, the tape drive 800 may initiate a process for handling a potentially damaged tape device 700. This process can include one or more of the following steps: immediately ejecting the potentially damaged tape device 700; downloading the data from the potentially damaged tape device 700 prior to ejection; transmitting a message to a user or a host system informing of the potentially damaged tape device 700; and performing diagnostic operations on the tape device to determine whether any damage has occurred.
The reflective region 750 of the shock indicator 710 may take various forms.
In addition, the dislodgeable body 730 may be formed in different ways. For example, in
In accordance with various embodiments, the shock indicator may be positioned in various locations within the tape device. When using a single-reel tape cartridge, it may be desirable to locate the shock indicator in an empty region in one of the corners of the tape cartridge.
The incorporation of human-perceivable shock indicators on data storage tape devices may improve the user's ability to easily identify potentially damaged data storage tape devices. This can be particularly useful, for example, when a user receives a shipment of new data storage tape devices that have been damaged in transit. The human-perceivable shock indicator can quickly indicate to a user prior to insertion into a tape drive whether a data storage tape device has been subjected to an unacceptable shock event and may potentially be damaged.
While the invention has been described in terms of particular embodiments and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the embodiments or figures described. For example, in some of the embodiments described above, the data storage tape device has been described as a tape cartridge. In other embodiments, the data storage tape device can be, for example, a tape cassette or other removable media.
As described above, the shock indicator may be responsive to a shock event of predetermined threshold. This threshold can be, for example, an acceleration of at least 45 g's (wherein 1 g=32 feet/sec2). In other embodiments, the shock threshold may be an acceleration of at least 50 g's, or 60 g's. In yet other embodiments, the shock threshold can be greater or lower.
The figures provided are merely representational and may not be drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. The figures are intended to illustrate various implementations of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.
Therefore, it should be understood that the invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration and that the invention be limited only by the claims and the equivalents thereof.
