Philip J. Erdelsky

Bio: Philip J. Erdelsky is an academic researcher. The author has contributed to research in topics: Mass storage & Magnetic tape data storage. The author has an hindex of 1, co-authored 1 publications receiving 276 citations.

Virtual addressing of optical storage media as magnetic tape equivalents

Abstract: An optical disk storage system emulates a magnetic tape subsystem by virtual addressing of data recorded on write once optical disk media having a predetermined group of available sectors for rewriting a disk ID, a predetermined plurality of bands of available sectors for rewriting a virtual tape directory to virtual tape VSNs, and, available sectors for rewriting virtual tape maps and rewriting user records, the tape maps have data portions for simulating tape marks and interblock gap and for addressing blocks of data within the virtual tapes, the virtual tape directory has pointers for pointing to tape maps, and the system rewrites the tape directory, tape maps and user records so as to function as a rewritable magnetic tape.

Network attached virtual tape data storage subsystem

Abstract: This data storage subsystem creates multiple virtual storage devices on demand, which are available to any and all of the system's host data processors. The subsystem utilizes a plurality of tape devices and automated tape libraries with the tape devices connected to a plurality of data processors via a high-speed network. A set of software components, the Network Storage Manager (NSM) controls all system operations. Depending upon the requested storage performance, one or more tape devices are assigned to a virtual device. Data stripping across multiple tape devices allows the storage bandwidth of a virtual device to be changed on demand. The overall capacity and performance of the subsystem is scalable by adding or removing storage devices. The NSM system controller contains a plurality of software elements including: Resource Allocation, Resource Configuration, Resource Management, and Security Management modules. The use of a networked storage manager enables the storage devices to be managed as a pool and yet be attached directly to the network as individual resources. The NSM also provides the mechanism for the enterprise management to control tape device allocation and configuration as well as other functions, such as tape cartridge movement, data migration and data security.

Systems and methods for performing data replication

Abstract: Performing data management operations on replicated data in a computer network. Log entries are generated for data management operations of an application executing on a source system. Consistency point entries are used to indicate a time of a known good, or recoverable, state of the application. A destination system is configured to process a copy of the log and consistency point entries to replicate data in a replication volume, the replicated data being a copy of the application data on the source system. When the replicated data represents a known good state of the application, as determined by the consistency point entries, the destination system(s) may perform a storage operation (e.g., snapshot, backup) to copy the replicated data and to logically associate the copied data with a time information (e.g., time stamp) indicative of the source system time when the application was in the known good state.

Modular backup and retrieval system used in conjunction with a storage area network

Abstract: A modular computer storage system and method is provided for managing and directing data archiving functions, which is scalable and comprehends various storage media as well as diverse operating systems on a plurality of client devices. A client component is associated with one or more client devices for generating archival request. A file processor directs one or more storage devices, through one or more media components, which control the actual physical level backup on various storage devices. Each media component creates a library indexing system for locating stored data. A management component coordinates the archival functions between the various client components and the file processor, including setting scheduling policies, aging policies, index pruning policies, drive cleaning policies, configuration information, and keeping track of running and waiting jobs.

Systems and methods for performing replication copy storage operations

Abstract: A system and method are provided for performing storage operations relating to a first secondary copy of electronic data. A storage policy or storage preferences may dictate that a replication copy should be used in storage operations performed to a particular client, sub-client, data, media or other item. Based on the storage policy, when a new client, sub-client, data, media or other item is received, a media agent determines whether there is a replication copy of the item. In the absence of a replication copy, one may be created. The replication copy may be provided by a third party application, or created by the client or a storage management system component. Information regarding the replication copy and its corresponding first secondary copy may be stored in a database. To optimize use of system resources, storage operations relating to the first secondary copy may be performed using the replication copy instead of the first secondary copy.

Rolling cache configuration for a data replication system

Abstract: Performing data management operations on replicated data in a computer network. Log entries are generated for data management operations of an application executing on a source system. Consistency point entries are used to indicate a time of a known good, or recoverable, state of the application. A destination system is configured to process a copy of the log and consistency point entries to replicate data in a replication volume, the replicated data being a copy of the application data on the source system. When the replicated data represents a known good state of the application, as determined by the consistency point entries, the destination system(s) may perform a storage operation (e.g., snapshot, backup) to copy the replicated data and to logically associate the copied data with a time information (e.g., time stamp) indicative of the source system time when the application was in the known good state.