NAME

sd − Disk driver for Adaptec ST-506 Disk Controllers

SYNOPSIS

controller sc0 at mb0 csr 0x80000 priority 2
disk sd0 at sc0 drive 0 flags 0
disk sd1 at sc0 drive 1 flags 0

DESCRIPTION

Files with minor device numbers 0 through 7 refer to various portions of drive 0.  The standard device names begin with “sd” followed by the drive number and then a letter a-h for partitions 0-7 respectively.  The character ? stands here for a drive number in the range 0-7. 

The block file’s 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 therefore raw I/O is considerably more effficient when many words are transmitted.  The names of the raw files conventionally begin with an extra ‘r.’

In raw I/O counts should be a multiple of 512 bytes (a disk sector).  Likewise seek calls should specify a multiple of 512 bytes. 

DISK SUPPORT

This driver handles all ST-506 drives, by reading a label from sector 0 of the drive which describes the disk geometry and partitioning. 

The sd?a partition is normally used for the root file system on a disk, the sd?b partition as a paging area, and the sd?c partition for pack-pack copying (it normally maps the entire disk).  The rest of the disk is normally the sd?h partition. 

FILES

/dev/sd[0-7][a-h]block files
/dev/rsd[0-7][a-h]raw files

SEE ALSO

dkio(4S)
Adaptec ACB 4000 and 5000 Series Disk Controllers OEM Manual

DIAGNOSTICS

sd%d%c: cmd how (msg) blk %d.  A command such as read or write encountered a error condition (how): either it failed, the unit was restored, or an operation was retry’ed.  The msg is derived from the error number given by the controller, indicating a condition such as “drive not ready” or “sector not found”. 

BUGS

In raw I/O read and write(2) truncate file offsets to 512-byte block boundaries, and write scribbles on the tail of incomplete blocks.  Thus, in programs that are likely to access raw devices, read, write and lseek(2) should always deal in 512-byte multiples.

Sun Release 1.1  —  Last change: 9 March 1984