Abstract: Method, system, and computer program product embodiments for recording data on a contactless integrated circuit (IC) memory associated with a data storage cartridge are provided. In one exemplary embodiment, an index of a plurality of files to be recorded on a storage media of the data storage cartridge is parsed with a table of contents (TOC) profile file to build a table of contents (TOC) specific to an owning application of the plurality of files. The TOC is written to the contactless IC memory.

Abstract: Provided are a computer program product, system, method, and data structure for compressing an input data stream. A determination is made of consecutive data units in the input data stream that match consecutive data units in a history buffer. A copy pointer symbol indicates a copy pointer symbol referencing previously received data units in the history buffer. A determination is made of a relative displacement count in the history buffer at which the number of matching consecutive data units start. A determination is made of a range of relative displacement counts comprising one of a plurality of ranges of displacement counts including the determined relative displacement count. A determination is made of the encoding scheme associated with the determined range. An encoding of the relative displacement count is determined from the determined encoding scheme. The determined encoding of the relative displacement count is indicated in the copy pointer.

Abstract: Provided are a computer program product, system, method, and data structure for using variable length code tables to compress an input data stream to a compressed output data stream. If a number of consecutive data units in the input data stream match the number of consecutive data units in a history buffer of previously received data units in the input data stream, a copy pointer symbol is generated indicating the copy pointer symbol referencing previously received data units in the history buffer and indicating a location of a start of the consecutive data units in the history buffer. A determination is made of an encoding of the number. Indication is made in the generated copy pointer symbol the determined encoding of the number and the copy pointer symbol is outputted in the compressed output data stream.

Abstract: Provided are a computer program product, system, method, and data structure for compressing an input data stream. A determination is made of consecutive data units in the input data stream that match consecutive data units in a history buffer. A copy pointer symbol indicates a copy pointer symbol referencing previously received data units in the history buffer. A determination is made of a relative displacement count in the history buffer at which the number of matching consecutive data units start. A determination is made of a range of relative displacement counts comprising one of a plurality of ranges of displacement counts including the determined relative displacement count. A determination is made of the encoding scheme associated with the determined range. An encoding of the relative displacement count is determined from the determined encoding scheme. The determined encoding of the relative displacement count is indicated in the copy pointer.

Abstract: According to one embodiment, a method includes storing instances of a file in a first storage tier and a second storage tier of a storage system, wherein the second storage tier uses less expensive and/or slower-to-access storage media than the first storage tier. Each instance of the file on the first and second storage tier is associated with a unique program identifier (UPI). A request to access the file or instance thereof is received from a user in a group of users, and a UPI associated with an instance of the file that exists on the first storage tier is searched for. Remote access to the instance of the file on the first storage tier is provided to the user requesting access to the file. Additional embodiments are also presented.

Abstract: According to one embodiment, a method includes storing instances of a file in a first storage tier and a second storage tier of a storage system; associating each instance of the file on the first and second storage tier with a unique program identifier (UPI); receiving a request to access the file or instance thereof from a user in a group of users; searching for a UPI associated with an instance of the file that exists on the first storage tier; and providing the user requesting access to the file with remote access to the instance of the file on the first storage tier. Additional methods are also presented.

Abstract: A method according to one embodiment includes receiving a command to mount a tape cartridge in a tape drive, mounting the tape cartridge in the tape drive, and determining that at least one special operation can be performed by the tape drive after mounting of the tape cartridge thereby. A first notification that the tape drive is in a not ready state is sent in response to determining the at least one special operation can be performed. The at least one special operation is performed. A second notification that the tape drive is in a ready state or an error state is sent after performing the at least one special operation.

Abstract: A storage system, according to one embodiment, includes a processor and logic integrated with and/or executable by the processor. The logic is configured to: search for an instance of a file or portion thereof on a second storage tier; at least one of: associate the instance of the file or portion thereof on the second storage tier with a first user when the instance of the file or portion thereof is not associated with any user, and replicate the instance of the file or portion thereof on the second storage tier and associate the replicated instance of the file or portion thereof on the second storage tier with the first user; and disassociate an instance of the file on a first storage tier from the first user.

Abstract: Provided are a computer program product, system, and method for generating a code alphabet for use by a deployed program to determine codewords for words. A first code alphabet is generated having a first number of symbols that provide variable length codings of the words. The symbols in the first code alphabet are merged into a second number of groups of the symbols in the first code alphabet, where the second number is less than the first number. A second code alphabet is generated having the second number of symbols, wherein a second average codeword length of the codewords produced using the symbols in the second code alphabet is smaller than the codeword length (b) of the words, and wherein the second code alphabet comprises the code alphabet used by the deployed program.

Abstract: Provided are a computer program product, system, method, and data structure for using variable length code tables to compress an input data stream to a compressed output data stream. If a number of consecutive data units in the input data stream match the number of consecutive data units in a history buffer of previously received data units in the input data stream, a copy pointer symbol is generated indicating the copy pointer symbol referencing previously received data units in the history buffer and indicating a location of a start of the consecutive data units in the history buffer. A determination is made from a variable length code table of an encoding of the number. Indication is made in the generated copy pointer symbol the determined encoding of the number and the copy pointer symbol is outputted in the compressed output data stream.

Abstract: 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.

Abstract: A storage system according to one embodiment includes logic integrated with and/or executable by a hardware processor, the logic being configured to: determine an ownership status for each of a plurality of instances of a file in a first storage tier and in a second storage tier of the storage system; determine locations of the instances of the file in the storage system; determine whether the instances of the file in the first storage tier are being accessed or not being accessed; and assign each of the instances of the file to one of a plurality of indices using the determined ownership status, location, and whether the instances are being accessed.

Abstract: A storage system according to one embodiment includes a first storage tier; a second storage tier; logic for storing instances of a file in the first storage tier and the second storage tier; logic for receiving a request to access the file or instance thereof from a user in a group of users; logic for providing the user requesting access to the file with remote access to an instance of the file on the first storage tier that is not being used by any other user in the group of users; logic for setting an ownership status of the instance of the file on the first storage tier to owned by the user requesting access to the file; and logic for setting an ownership status of an unused instance of the file on the second storage tier from owned by the user requesting access to the file to unowned or owned by a second user which previously owned the instance of the file on the first storage tier. Additional systems, methods, and computer program products are also presented.

Abstract: Provided are a computer program product, system, and method for generating a code alphabet for use by a deployed program to determine codewords for words. A first code alphabet has a first number of symbols that provide variable length codings of the words. A second code alphabet is generated having a second number of symbols formed by merging the symbols in the first code alphabet, wherein the second code alphabet comprises the code alphabet used by the deployed program.

Abstract: A storage system according to one embodiment includes a first storage tier; an intermediate storage tier; a second storage tier; logic for storing instances of a file in the first storage tier, the intermediate storage tier, and the second storage tier; logic for determining which of a plurality of instances of the file in the first storage tier are to be migrated to the second storage tier; logic for copying one instance of the file from the first storage tier to the intermediate storage tier; and logic for copying the instance of the file from the intermediate storage tier to the second storage tier for creating an instance of the file on the second storage tier for each instance of the file on the first storage tier that is to be migrated to the second storage tier. Additional systems, methods, and computer program products are also presented.

Abstract: A storage system according to one embodiment includes logic integrated with and/or executable by a hardware processor, the logic being configured to: determine an ownership status for each of a plurality of instances of a file in a first storage tier and in a second storage tier of the storage system; determine locations of the instances of the file in the storage system; determine whether the instances of the file in the first storage tier are being accessed or not being accessed; and assign each of the instances of the file to one of a plurality of indices using the determined ownership status, location, and whether the instances are being accessed.

Abstract: A storage system, according to one embodiment, includes a processor and logic integrated with and/or executable by the processor. The logic is configured to: search for an instance of a file or portion thereof on a second storage tier; at least one of: associate the instance of the file or portion thereof on the second storage tier with a first user when the instance of the file or portion thereof is not associated with any user, and replicate the instance of the file or portion thereof on the second storage tier and associate the replicated instance of the file or portion thereof on the second storage tier with the first user; and disassociate an instance of the file on a first storage tier from the first user.

Abstract: A storage system according to one embodiment includes a first storage tier; a second storage tier; logic for storing instances of a file in the first storage tier and the second storage tier; logic for determining an ownership status for each instance of the file in the storage system, wherein the ownership status includes owned and unowned; logic for determining a location of each instance of the file in the storage system; logic for determining whether each instance of the file in the first storage tier is being accessed or not being accessed; logic for assigning each instance of the file to one of a plurality of indices using the determined ownership status, location, and whether the instance is being accessed; logic for receiving a request to access the file or instance thereof from a user; logic for selecting an instance of the file based on an assignment of the instance of the file to one of the indices; and logic for providing the user with access to the selected instance of the file or copy thereof.

Abstract: A storage system according to one embodiment includes a first storage tier; a second storage tier; logic for storing instances of a file in the first storage tier and the second storage tier; logic for determining when to migrate an instance of the file associated with a first user and stored on the first storage tier to the second storage tier; logic for searching for an instance of the file or portion thereof on the second storage tier that is not associated with any user; logic for associating the instance of the file or portion thereof on the second storage tier with the first user; and logic for disassociating the instance of the file on the first storage tier from the first user. Additional systems, methods, and computer program products are also presented.

Abstract: 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.