1SI(4) Kernel Interfaces Manual SI(4)
2
6 si - SI 9500/CDC 9766 moving head disk
7
9 /sys/conf/SYSTEM:
10 NSI si_drives # SI 9500 driver for CDC 9766 disks
11 /etc/dtab:
13 #Name Unit# Addr Vector Br Handler(s) # Comments
14 si ? 176700 170 5 siintr # si9500
15 major device number(s):
17 raw: 18
18 block: 9
19 minor device encoding:
20 bits 0007 specify partition of SI drive
21 bits 0070 specify SI drive
22
24 Files with minor device numbers 0 through 7 refer to various portions
25 of drive 0; minor devices 8 through 15 refer to drive 1, etc. The
26 standard device names begin with ``si'' followed by the drive number
27 and then a letter a-h for partitions 0-7 respectively. The character ?
28 stands here for a drive number in the range 0-7.
29 The block files access the disk via the system's normal buffering mech‐
31 anism and may be read and written without regard to physical disk
32 records. There is also a `raw' interface which provides for direct
33 transmission between the disk and the user's read or write buffer. A
34 single read or write call results in exactly one I/O operation and
35 therefore raw I/O is considerably more efficient when many words are
36 transmitted. The names of the raw files conventionally begin with an
37 extra `r.'
38 In raw I/O the buffer must begin on a word (even) boundary, and counts
40 should be a multiple of 512 bytes (a disk sector). Likewise seek calls
41 should specify a multiple of 512 bytes.
42
44 The origin and size (in sectors) of the pseudo-disks on each drive are
45 as follows:
46 SI 9500/CDC9766 partitions:
48 disk start length cyls comments
49 xp?a 0 9120 0 - 14 /
50 xp?b 9120 9120 15 - 29 swap
51 xp?c 18240 234080 30 - 414
52 xp?d 252320 247906 415 - 822*
53 xp?e 18240 164160 30 - 299 /usr
54 xp?f 182400 152000 300 - 549
55 xp?g 334400 165826 550 - 822*
56 xp?h 0 500384 0 - 822 whole pack
57 Those partitions marked with an asterisk (``*'') actually stop short of
59 the indicated ending cylinder to protect any bad block forwarding
60 information on the packs. The indicated lengths are correct. Parti‐
61 tion ``h'' must be used to access the bad block forwarding area. N.B.:
62 the si driver does not support bad block forwarding; the space is
63 reserved in the event bad block forwarding is ever added to the driver.
64
66 /dev/si[0-7][a-h] block files
67 /dev/rsi[0-7][a-h] raw files
68 /dev/MAKEDEV script to create special files
69 /dev/MAKEDEV.local script to localize special files
70
72 hk(4), ra(4), ram(4), rk(4), rl(4), rp(4), rx(4), xp(4), dtab(5), auto‐
73 config(8)
74
76 si%d%c: hard error sn%d cnr=%b err=%b. An unrecoverable error occurred
77 during transfer of the specified sector of the specified disk parti‐
78 tion. The contents of the two error registers are also printed in
79 octal and symbolically with bits decoded. The error was either unre‐
80 coverable, or a large number of retry attempts (including offset posi‐
81 tioning and drive recalibration) could not recover the error.
82 si%d%c: hard error sn%d ssr=%b err=%b. An unrecoverable error occurred
84 during transfer of the specified sector of the specified disk parti‐
85 tion. The contents of the two error registers are also printed in
86 octal and symbolically with bits decoded. The error was either unre‐
87 coverable, or a large number of retry attempts (including offset posi‐
88 tioning and drive recalibration) could not recover the error.
89
91 In raw I/O read and write(2) truncate file offsets to 512-byte block
92 boundaries, and write scribbles on the tail of incomplete blocks.
93 Thus, in programs that are likely to access raw devices, read, write
94 and lseek(2) should always deal in 512-byte multiples.
95 The partition tables for the file systems should be read off of each
97 pack, as they are never quite what any single installation would pre‐
98 fer, and this would make packs more portable.
993rd Berkeley Distribution August 20, 1987 SI(4)