2.11BSD/man/cat4/si.0
SI(4) UNIX Programmer's Manual SI(4)
NAME
si - SI 9500/CDC 9766 moving head disk
SYNOPSIS
/sys/conf/SYSTEM:
NSI _s_i__d_r_i_v_e_s # SI 9500 driver for CDC 9766 disks
/etc/dtab:
#Name Unit# Addr Vector Br Handler(s) # Comments
si ? 176700 170 5 siintr # si9500
major device number(s):
raw: 18
block: 9
minor device encoding:
bits 0007 specify partition of SI drive
bits 0070 specify SI drive
DESCRIPTION
Files with minor device numbers 0 through 7 refer to various
portions of drive 0; minor devices 8 through 15 refer to
drive 1, etc. The standard device names begin with ``si''
followed by the drive number and then a letter a-h for par-
titions 0-7 respectively. The character ? stands here for a
drive number in the range 0-7.
The block files access the disk via the system's normal
buffering mechanism and may be read and written without
regard to physical disk records. There is also a `raw'
interface which provides for direct transmission between the
disk and the user's read or write buffer. A single read or
write call results in exactly one I/O operation and there-
fore raw I/O is considerably more efficient when many words
are transmitted. The names of the raw files conventionally
begin with an extra `r.'
In raw I/O the buffer must begin on a word (even) boundary,
and counts should be a multiple of 512 bytes (a disk sec-
tor). Likewise _s_e_e_k calls should specify a multiple of 512
bytes.
DISK SUPPORT
The origin and size (in sectors) of the pseudo-disks on each
drive are as follows:
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SI(4) UNIX Programmer's Manual SI(4)
SI 9500/CDC9766 partitions:
disk start length cyls comments
xp?a 0 9120 0 - 14 /
xp?b 9120 9120 15 - 29 swap
xp?c 18240 234080 30 - 414
xp?d 252320 247906 415 - 822*
xp?e 18240 164160 30 - 299 /usr
xp?f 182400 152000 300 - 549
xp?g 334400 165826 550 - 822*
xp?h 0 500384 0 - 822 whole pack
Those partitions marked with an asterisk (``*'') actually
stop short of the indicated ending cylinder to protect any
bad block forwarding information on the packs. The indi-
cated lengths are correct. Partition ``h'' must be used to
access the bad block forwarding area. N.B.: the _s_i driver
does not support bad block forwarding; the space is reserved
in the event bad block forwarding is ever added to the
driver.
FILES
/dev/si[0-7][a-h] block files
/dev/rsi[0-7][a-h] raw files
/dev/MAKEDEV script to create special files
/dev/MAKEDEV.local script to localize special files
SEE ALSO
hk(4), ra(4), ram(4), rk(4), rl(4), rp(4), rx(4), xp(4),
dtab(5), autoconfig(8)
DIAGNOSTICS
si%d%c: hard error sn%d cnr=%b err=%b. An unrecoverable
error occurred during transfer of the specified sector of
the specified disk partition. The contents of the two error
registers are also printed in octal and symbolically with
bits decoded. The error was either unrecoverable, or a
large number of retry attempts (including offset positioning
and drive recalibration) could not recover the error.
si%d%c: hard error sn%d ssr=%b err=%b. An unrecoverable
error occurred during transfer of the specified sector of
the specified disk partition. The contents of the two error
registers are also printed in octal and symbolically with
bits decoded. The error was either unrecoverable, or a
large number of retry attempts (including offset positioning
and drive recalibration) could not recover the error.
BUGS
In raw I/O _r_e_a_d and _w_r_i_t_e(2) truncate file offsets to 512-
byte block boundaries, and _w_r_i_t_e scribbles on the tail of
incomplete blocks. Thus, in programs that are likely to
access raw devices, _r_e_a_d, _w_r_i_t_e and _l_s_e_e_k(2) should always
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SI(4) UNIX Programmer's Manual SI(4)
deal in 512-byte multiples.
The partition tables for the file systems should be read off
of each pack, as they are never quite what any single
installation would prefer, and this would make packs more
portable.
Printed 11/26/99 August 20, 1987 3