.TH UDA 4V "9 February 1983" .UC 4 .SH NAME uda \- UDA-50 disk controller interface .SH SYNOPSIS .B "controller uda0 at uba0 csr 0172150 vector udintr" .br .B "disk ra0 at uda0 drive 0" .SH DESCRIPTION This is a driver for the DEC UDA-50 disk controller. The UDA-50 communicates with the host through a packet oriented protocol termed the Mass Storage Control Protocol (MSCP). Consult the file .RI < vax/mscp.h > for a detailed description of this protocol. .PP 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. .PP 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 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.' .PP In raw I/O counts should be a multiple of 512 bytes (a disk sector). Likewise .I seek calls should specify a multiple of 512 bytes. .SH "DISK SUPPORT" This driver handles all drives which may be connected to the UDA-50. Drive types per se are not recognized, but rather the variable length partitions are defined as having an ``infinite'' length and the controller is relied on to return an error when an inaccessible block is requested. For constructing file systems, however the partitions sizes are required. The origin and size (in sectors) of the pseudo-disks on each drive are as follows: .PP .nf .ta .5i +\w'000000 'u +\w'000000 'u +\w'000000 'u +\w'000000 'u .PP RA60 partitions disk start length cyls ra?a 0 15884 0-94 ra?b 15960 33440 95-294 ra?c 0 400176 0-2381 ra?d 49560 15884 295-389 ra?e 65520 55936 390-389 ra?f 121464 278586 723-2381 ra?g 49560 350490 295-2381 .PP RA80 partitions disk start length cyls ra?a 0 15884 0-36 ra?b 16058 33440 37-114 ra?c 0 242606 0-558 ra?d 49910 15884 115-151 ra?e 68096 55936 152-280 ra?f 125888 120559 281-558 ra?g 49910 192603 115-558 .PP RA81 partitions disk start length cyls ra?a 0 15884 0-22 ra?b 16422 66880 23-116 ra?c 0 891072 0-1247 ra?d 375564 15884 526-548 ra?e 391986 55936 549-979 ra?f 699720 191199 980-1247 ra?g 375564 515355 526-1247 ra?h 83538 291346 117-525 .DT .fi .PP It is unwise for all of these files to be present in one installation, since there is overlap in addresses and protection becomes a sticky matter. 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 copying (it maps the entire disk). On disks larger than about 205 Megabytes, the ra?h partition is inserted prior to the ra?d or ra?g partition; the ra?g partition then maps the remainder of the pack. All disk partition tables are calculated using the .IR diskpart (8) program. .SH FILES /dev/ra[0-9][a-f] .br /dev/rra[0-9][a-f] .SH DIAGNOSTICS .BR "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. .PP .BR "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. .PP .BR "uda%d: random interrupt ignored" . An unexpected interrupt was received (e.g. when no i/o was pending). The interrupt is ignored. .PP .BR "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. .PP .BR "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. .PP .BR OFFLINE . (Additional status information given after a hard i/o error.) A hard i/o error occurred because the driver was not on-line. .PP .BR "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. .PP .BR "uda: unknown packet" . An MSCP packet of unknown type was received from the UDA-50. Check the cabling to the controller. .PP The following errors are interpretations of MSCP error messages returned by the UDA-50 to the host. .PP .BR "uda%d: %s error, controller error, event 0%o" . .PP .BR "uda%d: %s error, host memory access error, event 0%o, addr 0%o" . .PP .BR "uda%d: %s error, disk transfer error, unit %d" . .PP .BR "uda%d: %s error, SDI error, unit %d, event 0%o" . .PP .BR "uda%d: %s error, small disk error, unit %d, event 0%o, cyl %d" . .PP .BR "uda%d: %s error, unknown error, unit %d, format 0%o, event 0%o" . .SH BUGS Doesn't appear to work well with multiple drives.