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145
Semantically-Smart Disk Systems
, 2003
"... We propose and evaluate the concept of a semantically-smart disk system (SDS). As opposed to a traditional "smart" disk, an SDS has detailed knowledge of how the file system above is using the disk system, including information about the on-disk data structures of the file system. An SDS e ..."
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Cited by 100 (13 self)
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We propose and evaluate the concept of a semantically-smart disk system (SDS). As opposed to a traditional "smart" disk, an SDS has detailed knowledge of how the file system above is using the disk system, including information about the on-disk data structures of the file system. An SDS exploits this knowledge to transparently improve performance or enhance functionality beneath a standard block read/write interface. To automatically acquire this knowledge, we introduce a tool (EOF) that can discover file-system structure for certain types of file systems, and then show how an SDS can exploit this knowledge on-line to understand file-system behavior. We quantify the space and time overheads that are common in an SDS, showing that they are not excessive. We then study the issues surrounding SDS construction by designing and implementing a number of prototypes as case studies; each case study exploits knowledge of some aspect of the file system to implement powerful functionality beneath the standard SCSI interface. Overall, we find that a surprising amount of functionality can be embedded within an SDS, hinting at a future where disk manufacturers can compete on enhanced functionality and not simply cost-per-byte and performance.
The DiskSim Simulation Environment Version 3.0 Reference Manual
, 2003
"... DiskSira is an efficient, accurate and highly-configurable disk system simulator developed to support research into various' aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers', buses, device drivers', request schedulers', ..."
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Cited by 88 (9 self)
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DiskSira is an efficient, accurate and highly-configurable disk system simulator developed to support research into various' aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers', buses, device drivers', request schedulers', disk block caches, and disk array data organizations'. In particular, the disk drive module simulates modern disk drives in great detail and has been carefully validated against several production disks (with accuracy that exceeds' any previously reported simulator).
Track-aligned Extents: Matching Access Patterns to Disk Drive Characteristics
- IN PROCEEDINGS OF THE 1ST USENIX SYMPOSIUM ON FILE AND STORAGE TECHNOLOGIES(FAST '02
, 2002
"... Track-aligned extents (traxtents) utilize disk-specific knowledge to match access patterns to the strengths of modern disks. By allocating and accessing related data on disk track boundaries, a system can avoid most rotational latency and track crossing overheads. Avoiding these overheads can incre ..."
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Cited by 86 (22 self)
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Track-aligned extents (traxtents) utilize disk-specific knowledge to match access patterns to the strengths of modern disks. By allocating and accessing related data on disk track boundaries, a system can avoid most rotational latency and track crossing overheads. Avoiding these overheads can increase disk access efficiency by up to 50 % for mid-sized requests (100-500 KB). This paper describes traxtents, algorithms for detecting track boundaries, and some uses of traxtents in file systems and video servers. For large-file workloads, a version of FreeBSD's FFS implementation that exploits traxtents reduces application run times by up to 20 % compared to the original version. A video server using traxtent-based requests can support 56 % more concurrent streams at the same startup latency and buffer space. For LFS, 44 % lower overall write cost for track-sized segments can be achieved.
The DiskSim Simulation Environment -- Version 2.0 Reference Manual
, 1999
"... DiskSim is an efficient, accurate and highly-configurable disk system simulator developed at the University of Michigan to support research into various aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers, buses, device drivers, request schedu ..."
Abstract
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Cited by 76 (5 self)
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DiskSim is an efficient, accurate and highly-configurable disk system simulator developed at the University of Michigan to support research into various aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers, buses, device drivers, request schedulers, disk block caches, and disk array data organizations. In particular, the disk drive module simulates modern disk drives in great detail and has been carefully validated against several production disks (with accuracy that exceeds any previously reported simulator). This manual
Trading Capacity for Performance in a Disk Array
- Symposium on Operating Systems Design and Implementation
, 2000
"... A variety of performance-enhancing techniques, such as striping, mirroring, and rotational data replication, exist in the disk array literature. Given a fixed budget of disks, one must intelligently choose which and what combination of these techniques to employ. In this paper, we present a way of d ..."
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Cited by 71 (4 self)
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A variety of performance-enhancing techniques, such as striping, mirroring, and rotational data replication, exist in the disk array literature. Given a fixed budget of disks, one must intelligently choose which and what combination of these techniques to employ. In this paper, we present a way of designing disk arrays that can flexibly and systematically reduce seek and rotational delay in a balanced manner. We give analytical models that can guide an array designer towards optimal configurations by considering both disk and workload characteristics. We have implemented a prototype disk array that incorporates the configuration models. In the process, we have also developed a robust disk head position prediction mechanism without any hardware support. The resulting prototype demonstrates the e#ectiveness of the configuration models. 1
Comparing Random Data Allocation and Data Striping in Multimedia Servers
- In ACM SIGMETRICS
, 2000
"... We compare performance of the RIO (Randomized I/O) Multimedia Storage Server which is based on random data allocation and block replication with traditional data striping techniques. We compare both approaches in terms of maximum supported data rate and stream cost. Data striping techniques in multi ..."
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Cited by 69 (1 self)
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We compare performance of the RIO (Randomized I/O) Multimedia Storage Server which is based on random data allocation and block replication with traditional data striping techniques. We compare both approaches in terms of maximum supported data rate and stream cost. Data striping techniques in multimedia servers are often designed for restricted workloads. e.g. sequential access patterns with CBR (constant bit rate) requirements. On other hand, RIO is designed to support virtually any type of multimedia application, including VBR (variable bit rate) video or audio, and interactive applications with unpredictable access patterns, such as 3D interactive virtual worlds, interactive scientific visualizations, etc. Surprisingly, our results show that system performance with random data allocation is competitive and sometimes even better than with data striping techniques, for the workloads for which data striping is designed to work best; i.e. streams with sequential access patterns and CBR...
Progress-Based Regulation of Low-Importance Processes
- In Proceedings of the Seventeenth ACM Symposium on Operating Systems Principles
, 1999
"... MS Manners is a mechanism that employs progress-based regulation to prevent resource contention with lowimportance processes from degrading the performance of high-importance processes. The mechanism assumes that resource contention that degrades the performance of a high-importance process will als ..."
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Cited by 54 (1 self)
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MS Manners is a mechanism that employs progress-based regulation to prevent resource contention with lowimportance processes from degrading the performance of high-importance processes. The mechanism assumes that resource contention that degrades the performance of a high-importance process will also retard the progress of the low-importance process. MS Manners detects this contention by monitoring the progress of the lowimportance process and inferring resource contention from a drop in the progress rate. This technique recognizes contention over any system resource, as long as the performance impact on contending processes is roughly symmetric. MS Manners employs statistical mechanisms to deal with stochastic progress measurements; it automatically calibrates a target progress rate, so no manual tuning is required; it supports multiple progress metrics from applications that perform several distinct tasks; and it orchestrates multiple low-importance processes to prevent measurement i...
A Modular, Analytical Throughput Model for Modern Disk Arrays
- International Workshop on Modeling, Analysis, and Simulation of Computer and Telecommunications Systems (Cincinnati, OH, 15–18 August 2001
, 2001
"... Enterprise storage systems depend on disk arrays for their capacity and availability needs. To design and maintain storage systems that efficiently satisfy evolving requirements, it is critical to be able to evaluate configuration alternatives without having to physically implement them. In this pap ..."
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Cited by 51 (4 self)
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Enterprise storage systems depend on disk arrays for their capacity and availability needs. To design and maintain storage systems that efficiently satisfy evolving requirements, it is critical to be able to evaluate configuration alternatives without having to physically implement them. In this paper, we describe an analytical model to predict disk array throughput, based on a hierarchical decomposition of the internal array architecture. We validate the model against a state-of-the-art disk array for a variety of synthetic workloads and array configurations. To our knowledge, no previously published analytical model has either incorporated the combined effects of the complex optimizations present in modern disk arrays, or been validated against a real, commercial array. Our results are quite encouraging for an analytical model: predictions are accurate in most cases within 32% of the observed array performance (15% on the average) for our set of experiments. 1
The DiskSim Simulation Environment -- Version 1.0 Reference Manual
, 1998
"... DiskSim is an efficient, accurate and highly-configurable disk system simulator developed at the University of Michigan to support research into various aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers, buses, device drivers, request schedu ..."
Abstract
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Cited by 50 (17 self)
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DiskSim is an efficient, accurate and highly-configurable disk system simulator developed at the University of Michigan to support research into various aspects of storage subsystem architecture. It includes modules that simulate disks, intermediate controllers, buses, device drivers, request schedulers, disk block caches, and disk array data organizations. In particular, the disk drive module simulates modern disk drives in great detail and has been carefully validated against several production disks (with accuracy that exceeds any previously reported simulator). This manual describes how to configure and use DiskSim, which has been made publicly available with the hope of advancing the state-of-the-art in disk system performance evaluation in the research community. The manual also briefly describes DiskSim's internal structure and various validation results.
