disk start length 0 0 23 1 23 21 2 0 0 3 0 0 4 44 386 5 430 385 6 44 367 7 44 771
If i is 1, the minor device consists of the specified pseudodisk on drives numbered 0 through the designated drive number. Successively numbered blocks are distributed across the drives in rotation.
Systems distributed for these devices use disk 0 for the root, disk 1 for swapping, and disk 4 (RP04/5) or disk 7 (RP06) for a mounted user file system.
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.
A `raw' interface 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 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 boundary, and raw I/O to an interleaved device is likely to have disappointing results.
Raw device drivers don't work on interleaved devices.