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c557cacd C |
1 | .if n .ND |
2 | .TL | |
3 | Performance Effects of Disk Subsystem Choices | |
4 | for VAX\(dg Systems Running 4.2BSD UNIX* | |
5 | .sp | |
6 | Revised July 27, 1983 | |
7 | .AU | |
8 | Bob Kridle | |
9 | .AI | |
10 | mt Xinu | |
11 | 2405 Fourth Street | |
12 | Berkeley, California 94710 | |
13 | .AU | |
14 | Marshall Kirk McKusick\(dd | |
15 | .AI | |
16 | Computer Systems Research Group | |
17 | Computer Science Division | |
18 | Department of Electrical Engineering and Computer Science | |
19 | University of California, Berkeley | |
20 | Berkeley, CA 94720 | |
21 | .AB | |
22 | .FS | |
23 | \(dgVAX, UNIBUS, and MASSBUS are trademarks of Digital Equipment Corporation. | |
24 | .FE | |
25 | .FS | |
26 | * UNIX is a trademark of Bell Laboratories. | |
27 | .FE | |
28 | .FS | |
29 | \(ddThis work was supported under grants from | |
30 | the National Science Foundation under grant MCS80-05144, | |
31 | and the Defense Advance Research Projects Agency (DoD) under | |
32 | Arpa Order No. 4031 monitored by Naval Electronic System Command under | |
33 | Contract No. N00039-82-C-0235. | |
34 | .FE | |
35 | Measurements were made of the UNIX file system | |
36 | throughput for various I/O operations using the most attractive currently | |
37 | available Winchester disks and controllers attached to both the | |
38 | native busses (SBI/CMI) and the UNIBUS on both VAX 11/780s and VAX 11/750s. | |
39 | The tests were designed to highlight the performance of single | |
40 | and dual drive subsystems operating in the 4.2BSD | |
41 | .I | |
42 | fast file system | |
43 | .R | |
44 | environment. | |
45 | Many of the results of the tests were initially counter-intuitive | |
46 | and revealed several important aspects of the VAX implementations | |
47 | which were surprising to us. | |
48 | .PP | |
49 | The hardware used included two Fujitsu 2351A | |
50 | ``Eagle'' | |
51 | disk drives on each of two foreign-vendor disk controllers | |
52 | and two DEC RA-81 disk drives on a DEC UDA-50 disk controller. | |
53 | The foreign-vendor controllers were Emulex SC750, SC780 | |
54 | and Systems Industries 9900 native bus interfaced controllers. | |
55 | The DEC UDA-50 controller is a UNIBUS interfaced, heavily buffered | |
56 | controller which is the first implementation of a new DEC storage | |
57 | system architecture, DSA. | |
58 | .PP | |
59 | One of the most important results of our testing was the correction | |
60 | of several timing parameters in our device handler for devices | |
61 | with an RH750/RH780 type interface and having high burst transfer | |
62 | rates. | |
63 | The correction of these parameters resulted in an increase in | |
64 | performance of over twenty percent in some cases. | |
65 | In addition, one of the controller manufacturers altered their bus | |
66 | arbitration scheme to produce another increase in throughput. | |
67 | .AE | |
68 | .LP | |
69 | .de PT | |
70 | .lt \\n(LLu | |
71 | .pc % | |
72 | .nr PN \\n% | |
73 | .tl '\\*(LH'\\*(CH'\\*(RH' | |
74 | .lt \\n(.lu | |
75 | .. | |
76 | .af PN i | |
77 | .ds LH Performance | |
78 | .ds RH Contents | |
79 | .bp 1 | |
80 | .if t .ds CF July 27, 1983 | |
81 | .if t .ds LF CSRG TR/8 | |
82 | .if t .ds RF Kridle, et. al. | |
83 | .ce | |
84 | .B "TABLE OF CONTENTS" | |
85 | .LP | |
86 | .sp 1 | |
87 | .nf | |
88 | .B "1. Motivation" | |
89 | .LP | |
90 | .sp .5v | |
91 | .nf | |
92 | .B "2. Equipment | |
93 | 2.1. DEC UDA50 disk controller | |
94 | 2.2. Emulex SC750/SC780 disk controllers | |
95 | 2.3. Systems Industries 9900 disk controller | |
96 | 2.4. DEC RA81 disk drives | |
97 | 2.5. Fujitsu 2351A disk drives | |
98 | .LP | |
99 | .sp .5v | |
100 | .nf | |
101 | .B "3. Methodology | |
102 | .LP | |
103 | .sp .5v | |
104 | .nf | |
105 | .B "4. Tests | |
106 | .LP | |
107 | .sp .5v | |
108 | .nf | |
109 | .B "5. Results | |
110 | .LP | |
111 | .sp .5v | |
112 | .nf | |
113 | .B "6. Conclusions | |
114 | .LP | |
115 | .sp .5v | |
116 | .nf | |
117 | .B Acknowledgements | |
118 | .LP | |
119 | .sp .5v | |
120 | .nf | |
121 | .B References | |
122 | .LP | |
123 | .sp .5v | |
124 | .nf | |
125 | .B "Appendix A | |
126 | A.1. read_8192 | |
127 | A.2. write_4096 | |
128 | A.3. write_8192 | |
129 | A.4. rewrite_8192 | |
130 | .ds RH Motivation | |
131 | .af PN 1 | |
132 | .bp 1 | |
133 | .de _d | |
134 | .if t .ta .6i 2.1i 2.6i | |
135 | .\" 2.94 went to 2.6, 3.64 to 3.30 | |
136 | .if n .ta .84i 2.6i 3.30i | |
137 | .. | |
138 | .de _f | |
139 | .if t .ta .5i 1.25i 2.5i | |
140 | .\" 3.5i went to 3.8i | |
141 | .if n .ta .7i 1.75i 3.8i | |
142 | .. |