UDA(4) UDA(4) NAME uda - UDA-50 disk controller interface SYNOPSIS controller uda0 at uba0 csr 0172150 vector udintr disk ra0 at uda0 drive 0 DESCRIPTION This is a driver for the DEC UDA-50 disk controller and for other com‐ patible controllers. The UDA-50 communicates with the host through a packet oriented protocol termed the Mass Storage Control Protocol (MSCP). Consult the file <_v_a_x_/_m_s_c_p_._h> for a detailed description of this protocol. 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 ‘‘ra’’ 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 files access the disk via the system’s normal buffering mech‐ anism 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 efficient 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 _s_e_e_k calls should specify a multiple of 512 bytes. DISK SUPPORT This driver configures the drive type of each drive when it is first opened. A partition table in the driver is required for each type of disk. The origin and size (in sectors) of the pseudo-disks on each drive are shown below. Not all partitions begin on cylinder bound‐ aries, as on other drives, because previous drivers used one partition table for all drive types. Variants of the partition tables are com‐ mon; check the driver and the file _/_e_t_c_/_d_i_s_k_t_a_b(_d_i_s_k_t_a_b(5)) for other possibilities. RC25 partitions disk start length ra?a 0 15884 ra?b 15884 10032 ra?c 0 50902 ra?g 25916 24986 RD52 partitions disk start length ra?a 0 15884 ra?b 15884 9766 ra?c 0 60480 ra?g 25650 34830 RD53 partitions disk start length ra?a 0 15884 ra?b 15884 33440 ra?c 0 138672 ra?g 49324 89348 ra?h 15884 122788 RA60 partitions disk start length ra?a 0 15884 ra?b 15884 33440 ra?c 0 400176 ra?d 49324 82080 same as 4.2BSD ra?g ra?e 131404 268772 same as 4.2BSD ra?h ra?f 49324 350852 ra?g 242606 157570 ra?h 49324 193282 RA80 partitions disk start length ra?a 0 15884 ra?b 15884 33440 ra?c 0 242606 ra?e 49324 193282 same as old Berkeley ra?g ra?f 49324 82080 same as 4.2BSD ra?g ra?g 49910 192696 ra?h 131404 111202 same as 4.2BSD RA81 partitions disk start length ra?a 0 15884 ra?b 16422 66880 ra?c 0 891072 ra?d 375564 15884 ra?e 391986 307200 ra?f 699720 191352 ra?g 375564 515508 ra?h 83538 291346 RA81 partitions with 4.2BSD-compatible partitions disk start length ra?a 0 15884 ra?b 16422 66880 ra?c 0 891072 ra?d 49324 82080 same as 4.2BSD ra?g ra?e 131404 759668 same as 4.2BSD ra?h ra?f 412490 478582 same as 4.2BSD ra?f ra?g 375564 515508 ra?h 83538 291346 The ra?a partition is normally used for the root file system, the ra?b partition as a paging area, and the ra?c partition for pack-pack copy‐ ing (it maps the entire disk). FILES /dev/ra[0-9][a-f] /dev/rra[0-9][a-f] DIAGNOSTICS uda: ubinfo %x. (VAX 11/750 only.) When allocating UNIBUS resources, the driver found it already had resources previously allocated. This indicates a bug in the driver. udasa %o, state %d. (Additional status information given after a hard i/o error.) The values of the UDA-50 status register and the internal driver state are printed. uda%d: random interrupt ignored. An unexpected interrupt was received (e.g. when no i/o was pending). The interrupt is ignored. uda%d: interrupt in unknown state %d ignored. An interrupt was received when the driver was in an unknown internal state. Indicates a hardware problem or a driver bug. uda%d: fatal error (%o). The UDA-50 indicated a ‘‘fatal error’’ in the status returned to the host. The contents of the status register are displayed. OFFLINE. (Additional status information given after a hard i/o error.) A hard i/o error occurred because the drive was not on-line. status %o. (Additional status information given after a hard i/o error.) The status information returned from the UDA-50 is tacked onto the end of the hard error message printed on the console. uda: unknown packet. An MSCP packet of unknown type was received from the UDA-50. Check the cabling to the controller. The following errors are interpretations of MSCP error messages returned by the UDA-50 to the host. uda%d: %s error, controller error, event 0%o. uda%d: %s error, host memory access error, event 0%o, addr 0%o. uda%d: %s error, disk transfer error, unit %d. uda%d: %s error, SDI error, unit %d, event 0%o. uda%d: %s error, small disk error, unit %d, event 0%o, cyl %d. uda%d: %s error, unknown error, unit %d, format 0%o, event 0%o. BUGS The partition tables attempt to combine compatibility with previous drivers and functionality; this is impossible. The best solution would be to read the partition tables off the drive. 4th Berkeley Distribution May 16, 1986 UDA(4)