DVHP(4) UNIX Programmer's Manual DVHP(4) NAME dvhp - Diva Comp V/Ampex 9300 moving-head disk 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 ``dvhp'' 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 origin and size of the partitions (in 512-byte sectors) on each drive are as follows: Partitions: disk start length cyls function on drive 0 dvhp?a 0 9405 0-14 / dvhp?b 9405 9405 15-29 swap dvhp?c 18810 241395 30-414 /usr dvhp?d 260205 250800 415-814 remainder of pack dvhp?e 18810 169290 30-299 alternate configuration dvhp?f 188100 156750 300-549 alternate configuration dvhp?g 313500 165528 550-814 alternate configuration dvhp?h 0 511005 0-814 whole pack Special files should only be created for the partitions that are actually used, as the overlap in these addresses could lead to confusion otherwise. 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 counts should be a multiple of 512 bytes (a disk sector). Likewise _l_s_e_e_k calls should specify a multiple of 512 bytes. FILES /dev/dvhp[0-7][a-h] block files /dev/rdvhp[0-7][a-h]raw files SEE ALSO hk(4), hp(4), hs(4), ml(4), rf(4), rk(4), rl(4), rm(4), rp(4), rx2(4), xp(4) Printed 5/17/83 1 DVHP(4) UNIX Programmer's Manual DVHP(4) DIAGNOSTICS dvhp%d%c: hard error bn %d cs2=%b er1=%b. An unrecoverable error occured 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. dvhp%d: write locked. The write protect switch was set on the drive when a write was attempted. The write operation is not recoverable. dvhp%d%c: soft ecc bn %d. A recoverable ECC error occurred on the specified sector of the specified disk partition. This happens normally a few times a week. If it happens more frequently than this the sectors where the errors are occuring should be checked to see if certain cylinders on the pack, spots on the carriage of the drive or heads are indicated. 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 deal in 512-byte multiples. DEC-standard error logging should be supported. Bad block forwarding is not yet supported. A program to analyze the logged error information (even in its present reduced form) is needed. 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 5/17/83 2