Tape Storage Research Articles

Determining storage for pressure-sensitive tape evidence: A long-term study.

Tape is a type of trace evidence commonly seen in forensic science. Little to no research has been published regarding the optimal storage material for pressure-sensitive adhesive (PSA) tape. The purpose of this project was to determine the substrate with the least amount of interference for storing PSA tape. Interferences such as difficulty removing tape from the substrate or substrate components leaching into the adhesive can affect the analysis. This was a long-term study in which samples were stored on various substrates for nearly 10 years. Ten different tape samples were placed on eight different substrates for a total of 80 samples. The substrates included typical materials currently used for tape storage as well as other, less common materials. The tape samples were evaluated for ease of removal at various time intervals. The adhesives from each tape were analyzed at similar time intervals by Fourier transform infrared spectroscopy (FTIR). In addition, the adhesives were analyzed by pyrolysis gas chromatography-mass spectrometry (PyGC-MS), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and x-ray fluorescence (XRF) at the last time interval (112 months) and compared to the adhesive tape samples from the original rolls of tape to determine if there was any adverse effect from the substrates during storage. The FedEx backing was the only substrate that had no adverse effects regarding ease of removal. The substrates that had the least effect on the adhesive for both short-term and long-term storage included FedEx backings, adhesive sheet backings, and polyester transparency sheets.

Bad Habits that Stick: An Investigation into Adhesive Medical Tape Use Practices and Beliefs

Background: Medical tape is one of the most ubiquitous resources in the hospital. Although tape is advertised by manufacturers as a single patient-use item, half-used rolls are a common sight in hospitals. Tape is often manipulated by un-sanitized and ungloved hands and comes in close contact with patient skin. Medical tape has the potential to be a source of hospital-acquired infection as it has been documented to be colonized with pathogens ranging from MRSA to Rhizopus. Despite infection risk, currently the only clinical guidelines of tape use are outlined in the Centers for Medicare & Medicaid Services guidance for Hemodialysis patients issued in 2008 that requires “tape should be dedicated to a single patient and discarded after use” as hemodialysis patients are at higher risk of infection. However, there is a lack of standards in the practice of tape use across hospital systems. Methods: To understand the current practices and beliefs of tape use at our institution, we developed a standardized survey to query individuals from various roles (RN, Physician, Patient Care Technicians, respiratory therapists, phlebotomists) across all patient care areas at a 746-bed academic, tertiary care center. Results: 52 units were surveyed, including 225 employees. Qualitative analysis revealed a wide variety of uses for medical tape for patient care, with venipuncture, securing IVs, and wound dressings being the most common. Only 1.4% of individuals reported single use of tape rolls. 54% of individuals reported tape use behaviors that carry an elevated risk for inoculation of pathogens. 70% of individuals reported that tape was discarded after the patient was discharged from their respective area. These practices did not change across procedure-heavy areas such as the Emergency Department or the Operating Rooms, in fact only 22% of individuals surveyed reported single use of tape in these areas. Beliefs about tape use varied: 95% of individuals agreed that a roll of tape could be used multiple times on a single patient, and 52% of individuals agreed that a roll of tape could be used on multiple patients. Conclusions: Tape use practices varied across hospital units, indicating the need for standardized policies for tape use and storage. Beliefs about tape not being a single-use item were consistent across the hospital and suggest that education and culture change efforts are needed to decrease the risk for hospital-acquired infections from improper medical tape use.

Inkjet-printed quantum dots on paper as concept towards high-density long-term data storage

Handling and storing the immense amounts of data native to the information age is a major challenge in terms of technological sustainability and energy demand. To date, tape storage remains the most widespread method for data archiving, while DNA data storage appears to offer the best data density and long-term stability in the future. However, DNA data storage is still in its infancy primarily due to economic and accessibility challenges. This emphasizes the need for more practical and readily available alternatives. We present a method for data storage utilizing inkjet printable quantum dots on paper with photoluminescence (PL) readout. Our proof of principle study showcases the ability to print and stack multiple bits of data on a single spot by exploiting the unique PL properties of quantum dots. This approach utilizes easily accessible resources, including a consumer-grade printer and paper as the substrate. Additionally, we perform initial stability tests, investigate scalability by controlling emission intensity, and evaluate the potential data density achievable by our approach.

Highly efficient utilization of polypyrrole enabled by dispersed buckypaper tape for high-performance flexible energy storage

This work develops a facile anodic treatment process to prepare dispersed buckypaper tape for the highly efficient utilization of polypyrrole towards durable flexible energy storage.

INFN and the evolution of distributed scientific computing in Italy

INFN and the evolution of distributed scientific computing in Italy

FTS Service Evolution and LHC Run-3 Operations

FTS Service Evolution and LHC Run-3 Operations

Efficient interface to the GridKa tape storage system

Efficient interface to the GridKa tape storage system

Enhancing data integrity and resilience: Extending the CERN backup system with a tape-based backend

The CERN IT Department is responsible for ensuring the integrity and security of data stored in the IT Storage Services. General storage backends such as EOS, CERNBox and CephFS are used to store data for a wide range of use cases for all stakeholders at CERN, including experiment project spaces and user home directories. In recent years a backup system, cback, was developed based on the open source backup program restic. cback is currently used to backup about 2.5 billion files and 18PB stored on disks in the CERN Computing Center. To significantly increase the reliability and security of the backups and reduce the storage costs, by limiting the amount of data on disk, we have added a tape storage backend to cback. With this addition cback can reliably be extended to new use cases, like backing up any local mountable file system, such as EOS, CephFS, NFS or DFS. In this paper we will describe the architecture and implementation of cback with the new tape storage backend and a number of developments planned for the near future.

Long-Term Performance of Magnetic Force Microscopy Tips Grown by Focused Electron Beam Induced Deposition

High-resolution micro- and nanostructures can be grown using Focused Electron Beam Induced Deposition (FEBID), a direct-write, resist-free nanolithography technology which allows additive patterning, typically with sub-100 nm lateral resolution, and down to 10 nm in optimal conditions. This technique has been used to grow magnetic tips for use in Magnetic Force Microscopy (MFM). Due to their high aspect ratio and good magnetic behavior, these FEBID magnetic tips provide several advantages over commercial magnetic tips when used for simultaneous topographical and magnetic measurements. Here, we report a study of the durability of these excellent candidates for high-resolution MFM measurements. A batch of FEBID-grown magnetic tips was subjected to a systematic analysis of MFM magnetic contrast for 30 weeks, using magnetic storage tape as a test specimen. Our results indicate that these FEBID magnetic tips operate effectively over a long period of time. The magnetic signal was well preserved, with a maximum reduction of 60% after 21 weeks of recurrent use. No significant contrast degradation was observed after 30 weeks in storage.

Between SC and LOGDCFL: families of languages accepted by logarithmic-space deterministic auxiliary depth-k storage automata

The closure of deterministic context-free languages under logarithmic-space many-one reductions (-m-reductions), known as LOGDCFL, has been studied in depth from an aspect of parallel computability because it is nicely situated between and . By replacing a memory device of pushdown automata with an access-controlled storage tape, we introduce a computational model of one-way deterministic depth-k storage automata (k-sda's) whose tape cells are freely modified during the first k accesses and then become blank forever. These k-sda's naturally induce the language family . Similarly to , we study the closure of all languages in under -m-reductions. We demonstrate that by significantly extending Cook's early result (1979) of . The entire hierarch of for all therefore lies between and . As an immediate consequence, we obtain the same simulation bounds for Hibbard's limited automata. We further characterize in terms of a new machine model, called logarithmic-space deterministic auxiliary depth-k storage automata that run in polynomial time. These machines are as powerful as a polynomial-time two-way multi-head deterministic depth-k storage automata. We also provide a ‘generic’ -complete language under -m-reductions by constructing a two-way universal simulator working for all k-sda's.

Optimal Data Decoding Strategies for Product-Coded Sequential Media Recording Via Latin Squares

In sequential media recording, such as found in tape data storage, data are typically accessed by reading signals from the beginning to the end of the recording medium in a streaming mode, which makes it unsuitable for random write accesses. However, sequential media is usually the preferred method for cold data storage in long-term data retention scenarios. In this study, we propose to increase the durability of sequential media by encoding data with locally recoverable codes (LRCs) both within and across different storage units creating a multidimensional product code external to the product code already implemented in the hardware. This way, local LRCs provide protection across the medium, whereas the LRCs spanning across different cartridges will provide global protection, which requires multiple drives and cartridges to help with the local decoding. Since global decoding is extremely costly, we require data allocation strategies that would use library resources efficiently. More specifically, we propose optimal data decoding and allocation strategies that would ensure minimum repair latency/communication cost in a global decoding setting for a given data request when local data reconstruction is not an option. We furthermore conduct analysis to find closed-form expressions and/or bounds on the overall latency/communication cost for product-coded systems under maintenance.

An Exact Algorithm for the Linear Tape Scheduling Problem

Magnetic tapes are often considered as an outdated storage technology, yet they are still used to store huge amounts of data. Their main interests are a large capacity and a low price per gigabyte, which come at the cost of a much larger file access time than on disks. With tapes, finding the right ordering of multiple file accesses is thus key to performance. Moving the reading head back and forth along a kilometer long tape has a non-negligible cost and unnecessary movements thus have to be avoided. However, the optimization of tape request ordering has rarely been studied in the scheduling literature, much less than I/O scheduling on disks. For instance, minimizing the average service time for several read requests on a linear tape remains an open question. Therefore, in this paper, we aim at improving the quality of service experienced by users of tape storage systems, and not only the peak performance of such systems. To this end, we propose a reasonable polynomial-time exact algorithm while this problem and simpler variants have been conjectured NP-hard. We also refine the proposed model by considering U-turn penalty costs accounting for inherent mechanical accelerations. Then, we propose a low-cost variant of our optimal algorithm by restricting the solution space, yet still yielding an accurate suboptimal solution. Finally, we compare our algorithms to existing solutions from the literature on logs of the mass storage management system of a major datacenter. This allows us to assess the quality of previous solutions and the improvement achieved by our low-cost algorithm. Aiming for reproducibility, we make available the complete implementation of the algorithms used in our evaluation, alongside the dataset of tape requests that is, to the best of our knowledge, the first of its kind to be publicly released.

Simulation and Evaluation of Cloud Storage Caching for Data Intensive Science

A common task in scientific computing is the data reduction. This workflow extracts the most important information from large input data and stores it in smaller derived data objects. The derived data objects can then be used for further analysis. Typically, these workflows use distributed storage and computing resources. A straightforward setup of storage media would be low-cost tape storage and higher-cost disk storage. The large, infrequently accessed input data are stored on tape storage. The smaller, frequently accessed derived data is stored on disk storage. In a best-case scenario, the large input data is only accessed very infrequently and in a well-planned pattern. However, practice shows that often the data has to be processed continuously and unpredictably. This can significantly reduce tape storage performance. A common approach to counter this is storing copies of the large input data on disk storage. This contribution evaluates an approach that uses cloud storage resources to serve as a flexible cache or buffer, depending on the computational workflow. The proposed model is explored for the case of continuously processed data. For the evaluation, a simulation tool was developed, which can be used to analyse models related to storage and network resources. We show that using commercial cloud storage can reduce on-premises disk storage requirements, while maintaining an equal throughput of jobs. Moreover, the key metrics of the model are discussed, and an approach is described, which uses the simulation to assist with the decision process of using commercial cloud storage. The goal is to investigate approaches and propose new evaluation methods to overcome future data challenges.

Development of Large Capacity Magnetic Tape Storage System

1．はじめに

Track-following system optimization for future magnetic tape data storage

Recently, the increase of track density has been shown to be one of the most effective methods to increase the areal bit density and thus the cartridge capacity of future magnetic tape data storage systems. Increasing the track density poses stringent positioning requirements to the tape track-following control system. In this work, we investigate four novel timing-based servo patterns, and the impact of their geometrical properties, i.e. azimuthal angle and subframe length, on the position estimation resolution, the system delay and track-following performance. First, the resolution of the patterns versus reader width is assessed by analyzing the noise floor in the power spectrum of the lateral position estimation. This methodology is used to determine the optimal reader width for each pattern. Second, the system delay for each of the new patterns is identified by measuring the frequency response of the track-following actuator. An analytical model of the delay is derived and verified with experimental data. Finally, the impact of resolution and delay on the track-following performance is investigated. The best track-following performance, characterized by a standard deviation of the position-error signal of 4.2nm, was achieved using a pattern with a 36°azimuthal angle. The performance could be further improved down to 4.0nm by time averaging the position estimates.

Development of Removable Visual Impact Indicator or Polymer Composite Materials

The prototype of removable visual impact indicator for thermoset polymer composite materials is developed, and its characteristics are experimentally determined. The indicator is a fabric tape glued by epoxy to the surface of the polymer composite. The tape is impregnated with a composition that provides a visual response at the place of an impact on the composite surface. Ball-drop tests demonstrated the increase of the magnitude of the visual response with the impact energy at different substrate hardnesses. The shelf-life and mode of the tape storage until commissioning are determined. Peel tests showed the ability to remove a used indicator without damaging the surface of the composite.

The benefits of migrating content to the cloud: How mass tape-to-cloud migration services helped the Rock & Roll Hall of Fame preserve music history

When the Rock & Roll Hall of Fame opened the doors on its library and archives in 2012, magnetic backup tape storage was the right solution for managing large files like the ones for its induction ceremonies, original concerts, education series and programmes. Over time, however, many of those tapes became less accessible due to hardware and software failures and onsite storage limitations. In 2018, after the Rock Hall evaluated its underlying technical infrastructure and needs, it decided to do what a growing number of organisations have been doing: migrate to the cloud. This case study examines how mass tape-to-cloud migration services helped the Rock Hall move data stored on Linear Tape-Open (LTO) tape storage to the cloud, where it can be preserved for years to come while being instantly accessible at any time and from anywhere.

The GridKa tape storage: latest improvements and current production setup

Tape storage remains the most cost-effective system for safe long-term storage of petabytes of data and reliably accessing it on demand. It has long been widely used by Tier-1 centers in WLCG. GridKa uses tape storage systems for LHC and non-LHC HEP experiments. The performance requirements on the tape storage systems are increasing every year, creating an increasing number of challenges in providing a scalable and reliable system. Therefore, providing high-performance, scalable and reliable tape storage systems is a top priority for Tier-1 centers in WLCG. At GridKa, various performance tests were recently done to investigate the existence of bottlenecks in the tape storage setup. As a result, several bottlenecks were identified and resolved, leading to a significant improvement in the overall tape storage performance. These results were achieved in a test environment and introduction of these achievements in to the production environment required a great effort, among many other things, a new software had to be developed to interact with the tape management software. This contribution provides detailed information on the latest improvements and changes on the GridKa tape storage setup.

CERN Tape Archive: a distributed, reliable and scalable scheduling system

The CERN Tape Archive (CTA) provides a tape backend to disk systems and, in conjunction with EOS, is managing the data of the LHC experiments at CERN.Magnetic tape storage offers the lowest cost per unit volume today, followed by hard disks and flash. In addition, current tape drives deliver a solid bandwidth (typically 360MB/s per device), but at the cost of high latencies, both for mounting a tape in the drive and for positioning when accessing non-adjacent files. As a consequence, the transfer scheduler should queue transfer requests before the volume warranting a tape mount is reached. In spite of these transfer latencies, user-interactive operations should have a low latency.The scheduling system for CTA was built from the experience gained with CASTOR. Its implementation ensures reliability and predictable performance, while simplifying development and deployment. As CTA is expected to be used for a long time, lock-in to vendors or technologies was minimized.Finally, quality assurance systems were put in place to validate reliability and performance while allowing fast and safe development turnaround.

Facile and Low-Temperature Synthesis of γ-Fe2O3 Nanoparticles with Thermally Stable Ferrimagnetism for Use in Magnetic Recording Tapes

Maghemite, γ-Fe2O3, has regained importance as a magnetic tape storage material for the big data era due to its low cost and long-term durability. However, the conventional synthesis of γ-Fe2O3, wh...