摘要:
A method, system and computer-usable medium are disclosed for reordering User Data Segment (UDS) lists to reduce seek times when accessing data stored on tape media. A host application sends a list of UDSs to a target tape drive and requests the tape drive to reorder the list to provide better performance. An ordered list of target User data Segments to retrieve from a target tape media is received. Information related to the location of each UDS on the target media is processed to determine its corresponding physical position on the tape media. The resulting physical positions are then processed to generate a reordered UDS list, where the order of the User Data Segments is reordered according to their physical location on the target tape media. The reordered list of User Data Segments is then used to perform seek, reposition and read operations to read User Data Segments from the tape media.
摘要:
A method, system and computer-usable medium are disclosed for reordering User Data Segment (UDS) lists to reduce seek times when accessing data stored on tape media. A host application sends a list of UDSs to a target tape drive and requests the tape drive to reorder the list to provide better performance. An ordered list of target User data Segments to retrieve from a target tape media is received. Information related to the location of each UDS on the target media is processed to determine its corresponding physical position on the tape media. The resulting physical positions are then processed to generate a reordered UDS list, where the order of the User Data Segments is reordered according to their physical location on the target tape media. The reordered list of User Data Segments is then used to perform seek, reposition and read operations to read User Data Segments from the tape media.
摘要:
A method for determining volume coherency is disclosed herein. Upon completing a first write job to a volume partition, the method makes a copy of a volume change reference (VCR) value associated with the volume. The VCR value is configured to change in a non-repeating manner each time content on the volume is modified. Prior to initiating a second write job to the volume partition, the method retrieves the copy and compares the copy to the VCR value. If the copy matches the VCR value, the method determines that a logical object on the partition was not modified between the first and second write jobs. If the copy does not match the VCR value, the method determines that the logical object on the partition was modified between the first and second write jobs. A corresponding system and computer program product are also disclosed herein.
摘要:
In one embodiment, a system includes a processor, logic in the processor and/or memory configured to determine a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, and logic configured to store an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto. In another embodiment, a method includes determining a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, storing an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto.
摘要:
In one embodiment, a system includes a processor, logic in the processor and/or memory configured to determine a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, and logic configured to store an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto. In another embodiment, a method includes determining a physical position on a magnetic medium that corresponds to an end of encrypted data written over residual unencrypted data, storing an indicator of the physical position on at least one of the magnetic medium and a memory coupled thereto.
摘要:
A system according to one embodiment includes a processor; logic in the processor and/or a memory configured to determine a furthest physical position on a magnetic medium that unobscured data has been written to; and logic configured to store an indicator of the furthest physical position on at least one of the magnetic medium and a memory coupled thereto. A system according to another embodiment includes a processor; logic in the processor and/or a memory configured to receive an instruction to obscure data on a magnetic medium; logic configured to read an indicator of a furthest physical position on the magnetic medium that unobscured data has been written to; and logic configured to cause obscuring of the unobscured data on the magnetic medium, and terminating the obscuring upon reaching the physical position in the indicator.
摘要:
A system according to one embodiment includes a processor; logic in the processor and/or a memory configured to determine a furthest physical position on a magnetic medium that unobscured data has been written to; and logic configured to store an indicator of the furthest physical position on at least one of the magnetic medium and a memory coupled thereto. A system according to another embodiment includes a processor; logic in the processor and/or a memory configured to receive an instruction to obscure data on a magnetic medium; logic configured to read an indicator of a furthest physical position on the magnetic medium that unobscured data has been written to; and logic configured to cause obscuring of the unobscured data on the magnetic medium, and terminating the obscuring upon reaching the physical position in the indicator.
摘要:
A method, system, and apparatus for re-conveying input/output (I/O) operations utilizing a sequential-access data storage device secondary communication port are disclosed. In accordance with one embodiment, a method is provided which comprises receiving an input/output (I/O) operation request via a first communication port of a primary data storage device, processing the I/O operation request utilizing the primary data storage device, and re-conveying the I/O operation request to a secondary data storage device substantially simultaneously with the processing via a second communication port of the primary data storage device. In the described embodiment, the primary data storage device comprises a sequential-access data storage device.
摘要:
A method, system and program are provided for enabling selective access to multiple users' encrypted data in a single storage cartridge. A unique, derived key is generated for each user's data by performing cryptographic operations on a combination of a common base key and metadata related to the data to be encrypted (e.g. its total block count). The base data key is wrapped with one or more encryption keys to form one or more encryption encapsulated data keys (EEDKs). The base key and the derived key are wrapped to create a session encrypted data key (SEDK), which along with the EEDKs, are conveyed to the tape drive, where the SEDK is decrypted. The EEDKs are then stored in one or more places on the storage cartridge. The base key and the derived key are used to encrypt a predetermined user's data, with the derived key stored on the cartridge with the encrypted data. The encrypted data may be subsequently decrypted by retrieving the EEDK and decrypting it with a decryption key to extract the base data key. The extracted base data key can then be used with other information to calculate the derived key. Once calculated, the derived key is used to decrypt its associated encrypted data.
摘要:
A method, system and program are provided for enabling access to encrypted data in a storage cartridge by wrapping the data key used to encrypt the data with one or more encryption keys (e.g., a public key from a public/private key pair) to form one or more encryption encapsulated data keys (EEDKs) and then storing the EEDK(s) on the storage cartridge along with the encrypted data. The encrypted data may be decoded by retrieving the EEDK from the storage cartridge, decrypting the EEDK with a decryption key (e.g., the private key from the public/private key pair) to extract the underlying data key, and then using the extracted data key to decrypt the encrypted data.