Redundant Arrays Of Inexpensive Disks Research Articles

Implementation of Live Forensic Method on Fusion Hard Disk Drive (HDD) and Solid State Drive (SSD) RAID 0 Configuration TRIM Features

One of the solutions used for access speeds is to maximize non-volatile storage functions by a conventional Hard Disk Driver with Solid State Drive that has the TRIM architecture using the Redundant Array of Inexpensive Disks 0 configuration or the commonly known RAID 0. RAID 0 is a stripping technique that has the highest speed among other RAID configurations. However, this configuration has a disadvantage in that when there is damage to one of the storage disks all the data will be corrupted and lost. It's becoming one of the challenges in digital forensic investigation when it comes to computer crime. Furthermore, this research uses experimental practices using live forensic methods to perform analysis and examination against the merger of HDD and SSD configuration RAID 0 TRIM features. The expected is an overview of the characteristics of recovery capability to find out the authenticity integrity values of files that have been lost or permanently deleted on both TRIM SSD functions disable and enable. Furthermore, this research is expected to be a solution for the experimental and practical investigation of computer crime especially in Indonesia given the increasing development of technology that is directly compared with the rise in computer crime.

Proactive Stripe Reconstruction to Improve Cache Use Efficiency of SSD-Based RAID Systems

Solid-State Drives (SSDs) exhibit different failure characteristics compared to conventional hard disk drives. In particular, the Bit Error Rate (BER) of an SSD increases as it bears more writes. Then, Parity-based Redundant Array of Inexpensive Disks (RAID) arrays composed from SSDs are introduced to address correlated failures. In the RAID-5 implementation, specifically, the process of parity generation (or update) associating with a data stripe, consists of read and write operations to the SSDs. Whenever a new update request comes to the RAID system, the related parity must be also updated and flushed onto the RAID component of SSD. Such frequent parity updates result in poor RAID performance and shorten the life-time of the SSDs. Consequently, a DRAM cache is commonly equipped accompanying with the RAID controller, called the parity cache, and used to buffer the parity chunks that are most frequently updated data, for boosting I/O performance. To better improve the use efficiency of the parity cache, this paper proposes a stripe reconstruction approach to minimize the number of parity updates on SSDs, thus boosting I/O performance of the SSD RAID system. When the currently updated stripe has both cold and hot updated data chunks, it will proactively carry out stripe reconstruction if we can find another matched stripe that also includes cold and hot update data chunks on the complementary RAID components. In the reconstruction process, we first group the cold data chunks of two matched stripes, to build a new stripe and flush the parity chunk on the RAID component. After that, the hot data chunks are organized as a new stripe as well, and its parity chunk is buffered in the parity cache. This results in better cache use efficiency, as it can reduce the number of parity updates on RAID components of SSDs, as well as proactively free up cache space for quickly absorbing subsequent write requests. In addition, the proposed method adjusts the target SSD of write requests based on stripe reconstructions through considering the I/O workload balance of all SSDs. Experimental results show that our proposal can reduce the number of parity chunk updates in SSDs by 2.3% and overall I/O latency by 12.2% on average, compared to state-of-the-art parity cache management techniques.

Demonstrating Redundancy Advantages of a Three-Channel Communication Protocol

Multi-Channel communications have the potential to provide advantages in security and redundancy. One widespread example of additional security is the use of 2 Factor Authentication wherein an authorization code is sent via a separate channel. As another example, spread spectrum technology offers resilience against channel interference. However, no currently deployed communication protocols take advantage of the full spectrum of security and performance gains that can be obtained through transmitting data over multiple channels. Taking inspiration from Redundant Array of Inexpensive Disks (RAID) and their use of data striping and mirroring, a secure multi-channel communication protocol was developed that is able to have greater security than an equivalent single channel system while also having greater resiliency against data corruption, therefore requiring fewer, if any, retransmissions than a single channel system when operating in a low availability environment. This approach admittedly comes with significant overhead, both in the use of additional channels and the need for additional processing. Whether the security and availability gains are worth the costs is an open question, with specific answers highly dependent on the particular applications. A specific multi-channel communication protocol, with three independent channels, and incorporating duplication on the bit level, was built and exercised within the OMNeT++ simulation environment in order to examine specific aspects of performance and security of the protocol. This exercise demonstrates that a secure multi-channel protocol operates with less latency than an equivalent single channel system when experiencing less than 50% channel corruption due to adversarial injection, resulting in reduced data loss and need for re-transmissions.

A STUDY ON LINUX KERNEL MODIFICATION FOR PERFORMANCE IMPROVEMENT OF SSD WEAR-OUT-AWARE SYSTEM

This study aims to improve the solid-state drive (SSD) wear-out-aware system by modifying the virtual file system (VFS) layer of the Linux kernel. Recently, according to the usage of big data and the development of artificial intelligence, the public can access it from a general PC rather than a research center. They installed several large-capacity SSDs required for learning individually or in a redundant array of inexpensive disks (RAID) 0 format on a PC to store the desired large amount of data. When multiple SSDs are connected and used, if one SSD suffers from wear-out, the input/output performance of other SSDs is adjusted to the corresponding device. Therefore, it is essential to ensure that wear out occurs evenly across multiple SSDs to prevent performance deterioration of the entire system. In this paper, we propose a method of distributing I/O to each SSD by modifying VFS layer of the Linux kernel to improve performance when the SSDs with the same performance but different performance due to wear-out. In other words, VFS was changed to detect each SSD wear out and distribute I/O to SSDs according to the performance ratio in a user-transparent way. Through the experimental results, when using the modified Linux kernel proposed in the paper, we found that the performance improved by 52% in the read and write functions compared to the original Linux kernel. Additionally, compared to RAID 0, it was found that there was a performance improvement of 26% in the read function and 16.7% in the write function. Keywords: Linux Kernel, Solid-State Drive, Redundant Array of Inexpensive Disks, Virtual File System DOI： https://doi.org/10.35741/issn.0258-2724.58.1.40

Cloud-oriented fault tolerance technique based on resource state

In this paper, we propose a new cloud reactive fault management technique called Hybrid Redundant Array of Independent resources for cloud computing (H_RAIC). The latter uses a new concept called Redundant Array of Independent resources for cloud computing (CRAIR), which is inspired by a powerful conventional technique called Redundant Arrays of Inexpensive Disks (RAID). H_RAIC takes into consideration the cloud resources state and aims to satisfy both cloud users and cloud provider requirements. Our solution was compared with the replication technique which represents a specific case of CRAIR, and with other CRAIR levels defined in this paper. The results show that our technique is a promising solution, that can be used to meet both user and provider requirements.

Mobile Cloud Storage Over 5G: A Mechanism Design Approach

In order to meet the increasing demand for the data storage, 5G wireless networks embodying mobile edge computing (MEC) features arise as a compelling solution. In this paper, the dense heterogeneous network (HetNet) and the MEC infrastructure are exploited to propose a mobile cloud storage framework that minimizes the data transmission delay. The proposed framework is composed of two parts: A data management with error correction (DMEC) scheme, and a radio resource management (RRM) scheme. The DMEC scheme, derived from the redundant array of inexpensive disks (RAID) technology, is implemented in the user equipment (UE) side, and it intelligently exploits the overlapping coverage of HetNet to minimize the transmission delay. On the other hand, the RRM scheme, based on mechanism design, presents the physical resource block allocation problem as a graph coloring problem and performs the radio resource allocation in multiuser scenario to maximize the network performance. The RRM scheme also comprises a pricing algorithm, which calculates the price a UE needs to pay for the resources. The proposed RRM scheme exhibits several desirable characteristics such as incentive compatibility, efficiency, and truthfulness, all derived from the Vickrey–Clarke–Groves mechanism. Simulation results are presented, showing that the proposed framework when compared to baseline techniques, minimizes the transmission delay by $10^2$ %, which places our proposal as effective and efficient solution for the mobile cloud storage problem.

Development of Full-Featured 8K Recorder

NHK has been researching a full-featured 8K ultrahigh-definition television system with a high frame rate of 120 Hz (8K/120 Hz) for future broadcasting. We have developed 8K encoder and decoder boards that support a popular video codec widely used in nonlinear editing (NLE). Installing these boards into our prototype 8K recorder realizes realtime 8K/120 Hz compression and decompression. The recorder can store 60 min of a compressed stream in a single removable memory with solid-state drives. We constructed an 8K post-production system and performed an 8K/120 Hz editing experiment with the recorded content. In the system, an NLE machine was connected to Redundant Arrays of Inexpensive Disks (RAID) devices through a high-speed interface appropriate for transferring a compressed 8K/120 Hz source. Common NLE software was used that works with 4K/60 Hz video reproduced from original 8K files by applying the resolution scalable decoding function of the codec, and the edited scenes were finally rendered at 8K/120 Hz system. With the 8K/120 Hz NLE system, approximately 350 min of footage was handled, and more than 100 min of content was mastered. To perform an 8K full-frame preview at editing sites, we also developed a peripheral playout module that incorporates a decoder for the recording codec and 8K/60 Hz output interface (quad-link 12G-SDI) in a single Peripheral Component Interconnect express (PCIe) card. By driving two modules in parallel, we achieved realtime 8K/120 Hz playout in a workstation. Furthermore, a compact removable memory with a nonvolatile memory express interface for offering good connectivity with editing systems was prototyped. These achievements can provide cost-efficient editing and playout, which makes 8K/120 Hz post-production more convenient than ever before.

A Fast Approach to Scale Up Disk Arrays With Parity Declustered Data Layout by Minimizing Data Migration

Parity declustering is widely deployed in erasure-coded storage systems so as to provide fast recovery and high data availability. However, to perform scaling on such redundant array of inexpensive disks (RAIDs), it is necessary to preserve parity declustered data layout so as to preserve the properties after scaling. Unfortunately, existing scaling algorithms fail to achieve this goal so they cannot be applied for scaling RAIDs with parity declustering. To address this challenge, we develop an efficient online scaling scheme called parity declustering scaling (PDS), which employs an auxiliary balanced incomplete block design to define the data migration so as to preserve parity declustered data layout. Furthermore, PDS can also be applied to scale RAIDs for improving reliability and/or storage efficiency as options by allocating more parity blocks and/or data blocks in stripes. We provide theoretical proofs to formally show that PDS preserves parity declustered data layout, and achieves uniform distributions of data and parity blocks after scaling while requiring only the minimal data migration. We implement PDS in Linux kernel 3.14.72 and evaluate its performance with real-world traces. The results show that PDS can reduce 82.37 percent of scaling time and 18.25 percent of user response time during scaling on average, compared with “moving-everything” round-robin approach adapted to achieve parity declustered data layout after scaling.

Reliability model of disk arrays RAID-5 with data striping

Within the scope of the this scientific paper, the simplified reliability model of disk arrays RAID-5 (redundant arrays of inexpensive disks) and an advanced reliability model offered by the authors taking into the consideration nonzero time of the faulty disk replacement and different failure rates of disks in normal state of the disk array and in degraded and rebuild states are discussed. The formula obtained by the authors for calculation of the mean time to data loss (MTTDL) of the RAID-5 disk arrays on basis of the advanced model is also presented. Finally, the technique of estimation of the initial reliability parameters, which are used in the reliability model, and the calculation examples of the mean time to data loss of the RAID-5 disk arrays for the different number of disks are also given.

Use of redundant arrays of inexpensive disks in orthodontic practice.

In a time when orthodontists are getting away from paper charts and going digital with their patient data and imaging, practitioners need to be prepared for a potential hardware failure in their data infrastructure. Although a backup plan in accordance with the Security Rule of the Health Insurance Portability and Accountability Act (HIPAA) of 1996 may prevent data loss in case of a disaster or hard drive failure, it does little to ensure business and practice continuity. Through the implementation of a common technique used in information technology, the redundant array of inexpensive disks, a practice may continue normal operations without interruption if a hard drive fails.

Performance Analysis of RAIDs in Storage Area Network

Direct Attached Storage, Network Attached Storage and Storage Area Network are the different kind of networking and storage facilities used in different domains from small scale industries to large scale industries. Storage area network is a disk system concentrated on network which allows clients or servers to use the disk system as a local disk. The speed of transmission of data to and from these systems is a crucial element in measuring the availability and reliability of the services provided by the industry. The redundancy of data is very important to provide high data availability; this can be achieved by having RAID (Redundant Array of Inexpensive Disks) methods. This paper describes the performance analysis on RAID levels 0,1,5,6 and10 through IOR benchmark tests on SAN which is implemented using ATA(Advanced Technology Attachment) over Ethernet protocol AoE(ATA over Ethernet). All these tests were performed on eight, 2-TB SAS (Serial Attached Storage) hard drives.

Beyond MTTDL

We introduce a new closed-form equation for estimating the number of data-loss events for a redundant array of inexpensive disks in a RAID-6 configuration. The equation expresses operational failures, their restorations, latent (sector) defects, and disk media scrubbing by time-based distributions that can represent non-homogeneous Poisson processes. It uses two-parameter Weibull distributions that allows the distributions to take on many different shapes, modeling increasing, decreasing, or constant occurrence rates. This article focuses on the statistical basis of the equation. It also presents time-based distributions of the four processes based on an extensive analysis of field data collected over several years from 10,000s of commercially available systems with 100,000s of disk drives. Our results for RAID-6 groups of size 16 indicate that the closed-form expression yields much more accurate results compared to the MTTDL reliability equation and matching computationally-intensive Monte Carlo simulations.

Q&A: RISC and reward

Having helped develop Reduced Instruction Set Computing and Redundant Arrays of Inexpensive Disks, David Patterson has set his sights on interdisciplinary research.

Strip-oriented asynchronous prefetching for parallel disk systems

Sequential prefetching schemes are widely employed in storage servers to mask disk latency and improve system throughput. However, existing schemes cannot benefit parallel disk systems as expected due to the fact that they ignore the distinct internal characteristics of the parallel disk system, in particular, data striping. Moreover, their aggressive prefetching pattern suffers from premature evictions and prolonged request latencies. In this paper, we propose a strip-oriented asynchronous prefetching (SoAP) technique, which is dedicated to the parallel disk system. It settles the above-mentioned problems by providing multiple novel features, e.g., enhanced prediction accuracy, adaptive prefetching strength, physical data layout awareness, and timely prefetching. To validate SoAP, we implement a prototype by modifying the software redundant arrays of inexpensive disks (RAID) under Linux. Experimental results demonstrate that SoAP can consistently offer improved average response time and throughput to the parallel disk system under non-random workloads compared with STEP, SP, ASP, and Linux-like SEQPs.

Flash-Aware RAID Techniques for Dependable and High-Performance Flash Memory SSD

Solid-state disks (SSDs), which are composed of multiple NAND flash chips, are replacing hard disk drives (HDDs) in the mass storage market. The performances of SSDs are increasing due to the exploitation of parallel I/O architectures. However, reliability remains as a critical issue when designing a large-scale flash storage. For both high performance and reliability, Redundant Arrays of Inexpensive Disks (RAID) storage architecture is essential to flash memory SSD. However, the parity handling overhead for reliable storage is significant. We propose a novel RAID technique for flash memory SSD for reducing the parity updating cost. To reduce the number of write operations for the parity updates, the proposed scheme delays the parity update which must accompany each data write in the original RAID technique. In addition, by exploiting the characteristics of flash memory, the proposed scheme uses the partial parity technique to reduce the number of read operations required to calculate a parity. We evaluated the performance improvements using a RAID-5 SSD simulator. The proposed techniques improved the performance of the RAID-5 SSD by 47 percent and 38 percent on average in comparison to the original RAID-5 technique and the previous delayed parity updating technique, respectively.

RAID: A Personal Recollection of How Storage Became a System

Randy H. Katz, David Patterson, and Garth Gibson first defined the acronym RAID, or redundant arrays of inexpensive disks, in a 1987 paper. The RAID idea was that it was feasible to achieve significantly higher levels of storage reliability from possibly very large numbers of lower-cost and lower-reliability smaller disk drives, which were then emerging for personal computers. Today, the National Academy includes RAID among the technologies created by federally funded research in universities that have led to multibillion dollar industries, and software implemented RAID is a standard component of modern operating systems. Here, Katz chronicles his experiences and contributions to RAID's early development.

Database management and partitioning to improve database processing performance

The technologies of searching methods are very important in database management systems, in that they must be a simple and practical way of managing problems in database systems. These methods must allow databases to be more easily deployed with optimal performance. The vertical and horizontal database partitioning are used to improve database performance. The horizontal method is more efficient than the vertical method in a large database, and it will be more efficient if distributed in more than one computer. Redundant Arrays of Inexpensive Disks (RAID) is one of the important technologies used in processing database. The proposed method was implemented to get optimal utilization of RAID level 1, by partitioning vertically the original database before storing them on RAID level 1, in order to get faster database retrieving while at the same time keeping the mirror technique of the RAID level 1 without any changes.

A Highly Accurate Method for Assessing Reliability of Redundant Arrays of Inexpensive Disks (RAID)

The statistical bases for current models of RAID reliability are reviewed and a highly accurate alternative is provided and justified. This new model corrects statistical errors associated with the pervasive assumption that system (RAID group) times to failure follow a homogeneous Poisson process, and corrects errors associated with assuming the time-to-failure and time-to-restore distributions are exponentially distributed. Statistical justification for the new model uses theory for reliability of repairable systems. Four critical component distributions are developed from field data. These distributions are for times to catastrophic failure, reconstruction and restoration, read errors, and disk data scrubs. Model results have been verified and predict between 2 to 1,500 times as many double disk failures as estimates made using the mean time to data loss method. Model results are compared to system level field data for RAID group of 14 drives and show excellent correlation and greater accuracy than either MTTDL.

Hard Disk Drives: The Good, the Bad and the Ugly!

HDDs are like the bread in a peanut butter and jelly sandwich—sort of an unexciting piece of hardware necessary to hold the “software.” They are simply a means to an end. HDD reliability, however, has always been a significant weak link, perhaps the weak link, in data storage. In the late 1980s people recognized that HDD reliability was inadequate for large data storage systems so redundancy was added at the system level with some brilliant software algorithms, and RAID (redundant array of inexpensive disks) became a reality. RAID moved the reliability requirements from the HDD itself to the system of data disks. Commercial implementations of RAID range from n+1 configurations (mirroring) to the more common RAID-4 and RAID-5, and recently to RAID-6, the n+2 configuration that increases storage system reliability using two redundant disks (dual parity). Additionally, reliability at the RAID group level has been favorably enhanced because HDD reliability has been improving as well.

Zoned-RAID

The RAID (Redundant Array of Inexpensive Disks) system has been widely used in practical storage applications for better performance, cost effectiveness, and reliability. This study proposes a novel variant of RAID named Zoned-RAID (Z-RAID). Z-RAID improves the performance of traditional RAID by utilizing the zoning property of modern disks which provides multiple zones with different data transfer rates within a disk. Z-RAID levels 1, 5, and 6 are introduced to enhance the effective data transfer rate of RAID levels 1, 5, and 6, respectively, by constraining the placement of data blocks in multizone disks. We apply the Z-RAID to a practical and popular application, streaming media server, that requires a high-data transfer rate as well as a high reliability. The analytical and experimental results demonstrate the superiority of Z-RAID to conventional RAID. Z-RAID provides a higher effective data transfer rate in normal mode with no disadvantage. In the presence of a disk failure, Z-RAID still performs as well as RAID.