Striping on Disks

Author(s):  
Phillip K.C. Tse

Multimedia streams need continuous data supply. The aggregate data access requirement of many multimedia streams imposes very high demand on the access bandwidth of the storage servers. The disk striping or data striping methods spreads data over multiple disks to provide high aggregate disk throughput (Chua, Li, Ooi, & Tan, 1996; Hsieh, Lin, Liu, Du, & Ruwart, 1995). In addition to the popularity of multimedia objects that we have described in the last chapter, multimedia streams consume an object in a sequential manner. The striping methods make use of this access pattern to evenly spread the workload across disks. This can increase aggregate disk throughput so that high bandwidth streams can be delivered continuously. We first describe the simple striping method that places data stripes on a set of disks in the next section. After that, the staggered striping method that places data on a set of disks in a rotating manner is described. The pseudorandom placement method that stores data stripes on random disks is explained before we summarize this chapter.

2022 ◽  
Vol 17 (01) ◽  
pp. C01040
Author(s):  
C. Zhao ◽  
D. Guo ◽  
Q. Chen ◽  
N. Fang ◽  
Y. Gan ◽  
...  

Abstract This paper presents the design and the test results of a 25 Gbps VCSEL driving ASIC fabricated in a 55 nm CMOS technology as an attempt for the future very high-speed optical links. The VCSEL driving ASIC is composed of an input equalizer stage, a pre-driver stage and a novel output driver stage. To achieve high bandwidth, the pre-driver stage combines the inductor-shared peaking structure and the active-feedback technique. A novel output driver stage uses the pseudo differential CML driver structure and the adjustable FFE pre-emphasis technique to improve the bandwidth. This VCSEL driver has been integrated in a customized optical module with a VCSEL array. Both the electrical function and optical performance have been fully evaluated. The output optical eye diagram has passed the eye mask test at the data rate of 25 Gbps. The peak-to-peak jitter of 25 Gbps optical eye is 19.5 ps and the RMS jitter is 2.9 ps.


Author(s):  
Phillip K.C. Tse

The data striping technique has been successfully applied on disks to reduce the time to access objects from the disks as shown in Chapter VI. Similarly, the striping technique has been investigated to reduce the time to access objects from the tape libraries. Similar to the striping on disks, the objective of the parallel striping method is to reduce the time to access objects from the tape libraries. The parallel tape striping directly applies the striping technique to place data stripes on tapes. The triangular placement method changes the order in which data stripes are stored on tapes to further enhance the performance. In the next section, the parallel tape striping method will be described. The performance of the parallel tape striping follows. After that, the triangular placement method is explained, and it is followed by the performance of the triangular placement method.


Author(s):  
Brian D. Krosschell ◽  
Stephen J. Klick ◽  
John J. Moskwa

The goal of this research is to use a hydrostatic transient dynamometer combined with new control techniques to replicate multi-cylinder engine dynamics which occur while the engine is started by an electric starting system. The transient engine dynamometer test system in the Powertrain Control Research Laboratory (PCRL) uses a torque tube and extremely stiff driveline in order to provide a very high bandwidth of torque actuation. The design and nature of this low inertia, stiff system requires that a standard electrical starting system be omitted. One of the objectives of this research was to assemble a new engine on the hydrostatic dynamometer and model the starting dynamics which occur during an engine cold start. The other objective was to verify and compare data collected by the PCRL and Ford to validate testing. This information will then be used in support of development of a cold start testing procedure on the single-cylinder engine transient test system in the PCRL.


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