173 research outputs found
Flash-memories in Space Applications: Trends and Challenges
Nowadays space applications are provided with a processing power absolutely overcoming the one available just a few years ago. Typical mission-critical space system applications include also the issue of solid-state recorder(s). Flash-memories are nonvolatile, shock-resistant and power-economic, but in turn have different drawbacks. A solid-state recorder for space applications should satisfy many different constraints especially because of the issues related to radiations: proper countermeasures are needed, together with EDAC and testing techniques in order to improve the dependability of the whole system. Different and quite often contrasting dimensions need to be explored during the design of a flash-memory based solid- state recorder. In particular, we shall explore the most important flash-memory design dimensions and trade-offs to tackle during the design of flash-based hard disks for space application
Flash-memories in Space Applications: Trends and Challenges
Nowadays space applications are provided with a processing power absolutely overcoming the one available just a few years ago. Typical mission-critical space system applications include also the issue of solid-state recorder(s). Flash-memories are nonvolatile, shock-resistant and power-economic, but in turn have different drawbacks. A solid-state recorder for space applications should satisfy many different constraints especially because of the issues related to radiations: proper countermeasures are needed, together with EDAC and testing techniques in order to improve the dependability of the whole system. Different and quite often contrasting dimensions need to be explored during the design of a flash-memory based solid- state recorder. In particular, we shall explore the most important flash-memory design dimensions and trade-offs to tackle during the design of flash-based hard disks for space applications
Investigating Power Outage Effects on Reliability of Solid-State Drives
Solid-State Drives (SSDs) are recently employed in enterprise servers and
high-end storage systems in order to enhance performance of storage subsystem.
Although employing high speed SSDs in the storage subsystems can significantly
improve system performance, it comes with significant reliability threat for
write operations upon power failures. In this paper, we present a comprehensive
analysis investigating the impact of workload dependent parameters on the
reliability of SSDs under power failure for variety of SSDs (from top
manufacturers). To this end, we first develop a platform to perform two
important features required for study: a) a realistic fault injection into the
SSD in the computing systems and b) data loss detection mechanism on the SSD
upon power failure. In the proposed physical fault injection platform, SSDs
experience a real discharge phase of Power Supply Unit (PSU) that occurs during
power failure in data centers which was neglected in previous studies. The
impact of workload dependent parameters such as workload Working Set Size
(WSS), request size, request type, access pattern, and sequence of accesses on
the failure of SSDs is carefully studied in the presence of realistic power
failures. Experimental results over thousands number of fault injections show
that data loss occurs even after completion of the request (up to 700ms) where
the failure rate is influenced by the type, size, access pattern, and sequence
of IO accesses while other parameters such as workload WSS has no impact on the
failure of SSDs.Comment: Design, Automation & Test in Europe Conference & Exhibition (DATE),
2018. IEEE, 201
Retrospective: Flipping Bits in Memory Without Accessing Them: An Experimental Study of DRAM Disturbance Errors
Our ISCA 2014 paper provided the first scientific and detailed
characterization, analysis, and real-system demonstration of what is now
popularly known as the RowHammer phenomenon (or vulnerability) in modern
commodity DRAM chips, which are used as main memory in almost all modern
computing systems. It experimentally demonstrated that more than 80% of all
DRAM modules we tested from the three major DRAM vendors were vulnerable to the
RowHammer read disturbance phenomenon: one can predictably induce bitflips
(i.e., data corruption) in real DRAM modules by repeatedly accessing a DRAM row
and thus causing electrical disturbance to physically nearby rows. We showed
that a simple unprivileged user-level program induced RowHammer bitflips in
multiple real systems and suggested that a security attack can be built using
this proof-of-concept to hijack control of the system or cause other harm. To
solve the RowHammer problem, our paper examined seven different approaches
(including a novel probabilistic approach that has very low cost), some of
which influenced or were adopted in different industrial products.
Many later works from various research communities examined RowHammer,
building real security attacks, proposing new defenses, further analyzing the
problem at various (e.g., device/circuit, architecture, and system) levels, and
exploiting RowHammer for various purposes (e.g., to reverse-engineer DRAM
chips). Industry has worked to mitigate the problem, changing both memory
controllers and DRAM standards/chips. Two major DRAM vendors finally wrote
papers on the topic in 2023, describing their current approaches to mitigate
RowHammer. Research & development on RowHammer in both academia & industry
continues to be very active and fascinating.
This short retrospective provides a brief analysis of our ISCA 2014 paper and
its impact.Comment: Selected to the 50th Anniversary of ISCA (ACM/IEEE International
Symposium on Computer Architecture), Commemorative Issue, 202
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