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In recent years, flash memory has become more widely used due to its advantages, such as fast data access, low power consumption, and high mobility. However, flash memory also has drawbacks that need to be overcome, such as erase-before-write, and the limitations of block deletion. In order to address this issue, the FTL (Flash Translation Layer) h...
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... engineers do not like to use it because of complex management and non-standard interface. The structure of NAND Flash memory is shown in Figure 1. ...
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... recovery structure of T*-ISLD includes the T*-tree index; the log directory as shown in Figure 10. The T*-tree algorithm is applied when inserting and retrieving data [9]. ...
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... example, <Insert, A, 20> is a command to insert key value of 20 to the node A. For failure recovery, the stored A, B, and C nodes in the flash memory are used to build the T*-tree, and then the log information is used to perform recovery before the failure. Figure 11. Failure Recovery Algorithm ...
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... this technique has a weakness in the capacity of flash memory that is not commensurate with the recovery time [17]. Figure 12 shows the crash recovery technique. ...
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... its recovery delay is lower than that of In-Page Backup because A-PLR uses a re-mapping table by browsing intermediate pages. Figure 13(a) shows the backup process and Figure 13(b) shows the recovery process of A-PLR. Figure 13. A-PLR (a) backup and (b) recovery process ...
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... its recovery delay is lower than that of In-Page Backup because A-PLR uses a re-mapping table by browsing intermediate pages. Figure 13(a) shows the backup process and Figure 13(b) shows the recovery process of A-PLR. Figure 13. A-PLR (a) backup and (b) recovery process ...
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... 13(a) shows the backup process and Figure 13(b) shows the recovery process of A-PLR. Figure 13. A-PLR (a) backup and (b) recovery process ...
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... reduce the recovery delay, HYFLUR uses three flush schemes, that is, MTF, URF, and SWF. Figure 14 shows three flush operations implemented with this timeline. MTF, URF, and SWF can be implemented with reasonable policies. ...
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... scheme assigns 6 bytes for each ppn so it can write 1365 ppns in 8KB memory. That means it can store mapping information of 1365 pages and Figure 15 briefly describes the URF operation. Figure 15. ...
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... means it can store mapping information of 1365 pages and Figure 15 briefly describes the URF operation. Figure 15. A brief description of URF operation If 8KB memory is full, the URF operation implemented also means approximately 1.3GB of flash memory is updated. ...
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... when the MTF executes, the new mapping is output using the mapping table and the MSB. Also, it saves the new table map information as shown in Figure 16. When MTF operation is executed, ppn is written to pages and these index pages become lpn (logical page number) so this scheme can build a mapping table by reading TSB. ...
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... compression algorithm Lempl-Ziv-Storer-Szymanski (LZSS), with improvements from LZ77 [20] is applied to the HYFLUR algorithm to address the spatial cost of a project page mapping vulnerability. Figure 17 shows the RAM configuration when the first RAM is full, the compression process is performed and compressed data is stored in 2 nd RAM. This process repeated three times to make 2 nd RAM full. ...
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... operation occurs when MSB is full because of the URF operation. Figure 19 shows new compressed mapping table information and write the ppn in pages of TSB. For example, when MTF operation is executed, new ppn is written to pages and these pages index becomes lpn. ...
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... compressed three 8KB pages and write them to one page of TSB so that total 8190 ppn can be stored in on one page. Figure 19. The structure of TSB C-HYFLUR is implemented on open SSD project board [21] and special hardware as follows. ...
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... engineers do not like to use it because of complex management and non-standard interface. The structure of NAND Flash memory is shown in Figure 1. ...
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... recovery structure of T*-ISLD includes the T*-tree index; the log directory as shown in Figure 10. The T*-tree algorithm is applied when inserting and retrieving data [9]. ...
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... example, <Insert, A, 20> is a command to insert key value of 20 to the node A. For failure recovery, the stored A, B, and C nodes in the flash memory are used to build the T*-tree, and then the log information is used to perform recovery before the failure. Figure 11. Failure Recovery Algorithm ...
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... this technique has a weakness in the capacity of flash memory that is not commensurate with the recovery time [17]. Figure 12 shows the crash recovery technique. ...
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... its recovery delay is lower than that of In-Page Backup because A-PLR uses a re-mapping table by browsing intermediate pages. Figure 13(a) shows the backup process and Figure 13(b) shows the recovery process of A-PLR. Figure 13. A-PLR (a) backup and (b) recovery process ...
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... its recovery delay is lower than that of In-Page Backup because A-PLR uses a re-mapping table by browsing intermediate pages. Figure 13(a) shows the backup process and Figure 13(b) shows the recovery process of A-PLR. Figure 13. A-PLR (a) backup and (b) recovery process ...
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... 13(a) shows the backup process and Figure 13(b) shows the recovery process of A-PLR. Figure 13. A-PLR (a) backup and (b) recovery process ...
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... reduce the recovery delay, HYFLUR uses three flush schemes, that is, MTF, URF, and SWF. Figure 14 shows three flush operations implemented with this timeline. MTF, URF, and SWF can be implemented with reasonable policies. ...
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... scheme assigns 6 bytes for each ppn so it can write 1365 ppns in 8KB memory. That means it can store mapping information of 1365 pages and Figure 15 briefly describes the URF operation. Figure 15. ...
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... means it can store mapping information of 1365 pages and Figure 15 briefly describes the URF operation. Figure 15. A brief description of URF operation If 8KB memory is full, the URF operation implemented also means approximately 1.3GB of flash memory is updated. ...
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... when the MTF executes, the new mapping is output using the mapping table and the MSB. Also, it saves the new table map information as shown in Figure 16. When MTF operation is executed, ppn is written to pages and these index pages become lpn (logical page number) so this scheme can build a mapping table by reading TSB. ...
Context 26
... compression algorithm Lempl-Ziv-Storer-Szymanski (LZSS), with improvements from LZ77 [20] is applied to the HYFLUR algorithm to address the spatial cost of a project page mapping vulnerability. Figure 17 shows the RAM configuration when the first RAM is full, the compression process is performed and compressed data is stored in 2 nd RAM. This process repeated three times to make 2 nd RAM full. ...
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... operation occurs when MSB is full because of the URF operation. Figure 19 shows new compressed mapping table information and write the ppn in pages of TSB. For example, when MTF operation is executed, new ppn is written to pages and these pages index becomes lpn. ...
Citations
... Creation of technical support. [32] ...
This review paper discusses the role of Virtual Machine for recovering data in digital forensic investigations. Virtual machine has been the one of most virtualization technology used today for working and saving hardware resources, besides as a tool conducts research on malware, network installations etc. It aims to expose limitations within commercial closed source of virtual machines and open source virtual machines. The wide use of virtualization technology is becoming a new challenge for digital forensics experts to carry out further research on the recovery of deleted virtual machine data. The review paper provides a brief overview of data recovery for digital forensic investigations and virtual environments, and concludes with an experiment with open source tools; the effects of the virtual machines on the host machine as well as the performance of the virtual machine itself. This review tries to find out whether there is evidence of generated activity in the destroyed virtual machine and how to find the potential of digital evidence by using the Virtual Machine Forensic Analysis and Data Recovery tools. Data recovery steps in when the convict damages or destroys the data storage devices, allowing for the data to be recovered from these artifacts. This paper focuses mostly on data recovery in cyber forensics and the different tools used to recover data through virtual machine.
... In this work, we examine early research on data recovery for flash memory, ranging from FTL processing techniques to PLR (power loss recovery) explanations that have been suggested by authors in conference proceedings, patents, or in scholarly magazines. This will include an overview and a review of the solutions that have been suggested for data recovery in flash memory [38]. The majority of flash storage systems have a FTL (flash translation layer), which is necessary to protect updated metadata from an unexpected power outage. ...
The flash storage is a type of nonvolatile semiconductor device that is operated continuously and has been substituting the hard disk or secondary memory in several storage markets, such as PC/laptop computers, mobile devices, and is also used as an enterprise server. Moreover, it offers a number of benefits, including compact size, low power consumption, quick access, easy mobility, heat dissipation, shock tolerance, data preservation during a power outage, and random access. Different embedded system products, including digital cameras, smartphones, personal digital assistants (PDA), along with sensor devices, are currently integrating flash memory. However, as flash memory requires unique capabilities such as “erase before write” as well as “wear-leveling”, a FTL (flash translation layer) is added to the software layer. The FTL software module overcomes the problem of performance that arises from the erase before write operation and wear-leveling, i.e., flash memory does not allow for an in-place update, and therefore a block must be erased prior to overwriting upon the present data. In the meantime, flash storage devices face challenges of failure and thus they must be able to recover metadata (as well as address mapping information), including data after a crash. The FTL layer is responsible for and intended for use in crash recovery. Although the power-off recovery technique is essential for portable devices, most FTL algorithms do not take this into account. In this paper, we review various schemes of crash recovery leveraging FTL for flash storage devices. We illustrate the classification of the FTL algorithms. Moreover, we also discuss the various metrics and parameters evaluated for comparison with other approaches by each scheme, along with the flash type. In addition, we made an analysis of the FTL schemes. We also describe meaningful considerations which play a critical role in the design development for power-off recovery employing FTL.
... (1) Therefore, hybrid CMOS circuits were proposed by many researchers for performance improvement [5][6][7][8][9][10][11]. The combination with memory characteristics of the memristors creates a unique opportunity for the next generation computers in which memory and logic devices blended to avoid a data bandwidth limitation between processing units and the memory [12,13]. Simulating the developed model of memristor was the best way to monitor the electrical properties as compared with the CMOS properties [14][15][16][17][18]. ...
In this paper, a hybrid memristor-CMOS implementation of logic gates simulated using LTSpice. Memristors' implementation in computer architecture designs explored in various design structures proposed by researchers from all around the world. However, all prior designs have some drawbacks in terms of applicability, scalability, and performance. In this research, logic gates design based on the hybrid memristor-CMOS structure presented. 2-inputs AND, OR, NAND, NOR, XOR, and XNOR are demonstrated with minimum components requirements. In addition, a 1-bit full adder circuit with high performance and low area consumption is also proposed. The proposed full adder only consists of 4 memristors and 7 CMOS transistors. Half design of the adder base on the memristor component created. Through analysis and simulations, the memristor implementation on designing logic gates using memristor-CMOS structure demonstrated using the generalized metastable switch memristor (MSS) model and LTSpice. In conclusion, the proposed approach improves speed and require less area.
... Therefore, the recovery time overhead of C-HYFLUR is lessening than A-PLR and HYFLUR. Nevertheless, the adding page write operations and compression process are necessary, the response time is longer than A-PLR and HYFLUR [14]. ...
... Thus, the recovery time cost of C-HYFLUR is lesser than A-PLR and HYFLUR. Hence, the append page writing operations and compression process are necessary; the response time is larger than A-PLR and HYFLUR [19]. ...
Flash memory has been built upon EEPROM (Electronically Erasable Programmable Read-Only Memory). Unlike traditional magnetic disks, Flash memory has disadvantages, like the limitations of life cycle and erase-before-write, which require a resolution well-known namely Flash Translation Layer (FTL) to resolve. Volatile memory today is used to save periodic retrieve requests for mapping tables in flash memory. These tables can be missed when an unexpected power outage occurs. In order to address this problem, Page-mapping, Block-mapping, and Hybrid-mapping methods have been introduced. However, these methods also have shortcomings, for example, the mapping-information management overhead and the recovery time. In this paper, we introduce a data recovery scheme that improves on Hybrid-mapping together with the spare area separate to ECC (Error Code Correction), block information, ASN (Allocation Sequence Number), mapping-information, Flag, and reserved in FTL. The results display that our technique has less recovery time and mapping-information management overhead than the previous methods.
