04/21/86 init_vol Syntax as a command: init_vol volume_name drive_name {-control_arg} Function: writes the label of a new physical volume and sets up its VTOC and volume map. This operation destroys any previous contents of the physical volume. This command can be used in ring 1 or ring 4. It is also automatically entered when a cold boot is done to initialize the RPV. Arguments: volume_name is the name of a physical volume. drive_name has the form _{s}, where: subsys is the disk subsystem name (dska) nn is the device number. (00 to 64) s is the subvolume name, for MSU3380 or MSU3390 (a,b, or c). example: dska_02 or dskb_00b. Control arguments: -special enters dialogue with the user. The -special control argument is recommended for all RLV volumes. -copy initializes a copy of an already accepted physical volume (-copy also enters dialogue with the user). -rlv specifies that the physical volume is to be registered as part of the root logical volume. this control argument can be used only during a cold boot of the root physical volume at ring-1 initializer command level. Notes on special mode: Special mode is entered when -special is given on an init_vol command line, when the rebuild_disk command is used, or when a cold boot of the RPV is done. In special mode, the user may specify various parameters of the volume being initialized as other than their default values. Special mode uses a request loop subsystem to allow entry of these parameters. This includes the ability to specify the locations and extents of partitions. Defaults for volume initialized by init_vol or rebuild_disk command are no partitions and VTOC size constrained by average segment length of 5.0. Defaults for RPV initialized by cold boot sequence are partitions laid out on pack as follows. partition partition low/high name size (in records) end of pack HC 2500 low CONF 4 low FILE 255 high BCE 2200 high LOG 256 high DUMP 2000 high BOS 270 high ALT as needed high VTOC size constrained by average segment length of 2.0 For non-RPV packs belonging to the RLV, it is recommended that special mode be used to set an average segment length of 4.0 since directories, which reside on the RLV, are usually smaller than other segments. A smaller average segment length increases the number of VTOC entries (VTOCES) on the pack. Since it is easier to make the VTOC bigger than to make it smaller, the recommended procedure is to start with 4.0 as an average segment length. If more VTOCES are needed later, the rebuild_disk command can be used to define them. When using volume backup to recover the contents of a disk pack, make sure there are at least as many available records and total VTOC entries as there were on the physical volume before it was damaged. Notes on request loop of init_vol: The following request lines may be typed when init_vol is invoked with the -special control argument, when the rebuild_disk command is being used, or within the cold boot sequence. asl FFF.FF, avg FFF.FF specifies the average segment length, which is used to determine the VTOC size. As partitions are defined, the VTOC size is adjusted to maintain a VTOC entry to free page ratio producing this average segment length. When operating in this mode (the default, with average segment length = 5.0), the parameters are said to be constrained by average segment length. default causes all parameters to be reset to their cold boot defaults, including the list of partitions. This request is only valid within the cold boot sequence. end causes the command init_vol or rebuild_disk to proceed using the parameters as they stand at this point. help lists all requests available within the init_vol request loop. lace N specifies physical address assignment interlace; i.e., specifies that the system should try to place the pages of a segment N disk records apart on the target disk. The default value for N is 2. This request is only valid in the rebuild_disk command. list causes the current parameters to be listed, including partition data, VTOC size, number of VTOC entries and effective average segment length. Issuing other requests causes these parameters to change. When the request loop is entered, a list request is performed automatically. nvtoce N specifies the VTOC size by the number of VTOC entries to be created. As five VTOC entries occupy each page, this number is rounded up to the next five before use. This constrains parameters by VTOC size. part name hilow size where name is a 4-character or fewer partition name, hilow is either "high" or "low", and size is the partition size in records, defines a partition to be allocated on the pack. The hilow argument specifies which end of the pack, with respect to device address, the partition shall be allocated. Successive requests for "high" partitions receive successively lower addresses, and successive requests for "low" partitions receive successively higher addresses. Partitions may not be redefined without issuing the "startover" request. quit causes the command init_vol or rebuild_disk to be aborted, without initializing or rebuilding any disks. This request is not valid within the cold boot sequence. startover causes all parameters to be reset to their defaults (init_vol command defaults, not cold boot defaults). In particular, no partitions are defined, even in the cold boot environment. vtoc N specifies the total number of pages to be allocated for the volume header and volume table of contents (VTOC). All other space on the pack is available for paging and partitions. When the "vtoc" or "nvtoce" request is given, the parameters are said to be constrained by VTOC size, and average segment length varies as partitions are defined. Notes: The init_vol command queries the user before destroying the label of any pack that appears to be a validly labeled pack. A message giving the pack's physical volume name and time of last use is displayed. The init_vol command takes about 90 seconds for a model M400 disk. ----------------------------------------------------------- Historical Background This edition of the Multics software materials and documentation is provided and donated to Massachusetts Institute of Technology by Group BULL including BULL HN Information Systems Inc. as a contribution to computer science knowledge. This donation is made also to give evidence of the common contributions of Massachusetts Institute of Technology, Bell Laboratories, General Electric, Honeywell Information Systems Inc., Honeywell BULL Inc., Groupe BULL and BULL HN Information Systems Inc. to the development of this operating system. Multics development was initiated by Massachusetts Institute of Technology Project MAC (1963-1970), renamed the MIT Laboratory for Computer Science and Artificial Intelligence in the mid 1970s, under the leadership of Professor Fernando Jose Corbato. Users consider that Multics provided the best software architecture for managing computer hardware properly and for executing programs. Many subsequent operating systems incorporated Multics principles. Multics was distributed in 1975 to 2000 by Group Bull in Europe , and in the U.S. by Bull HN Information Systems Inc., as successor in interest by change in name only to Honeywell Bull Inc. and Honeywell Information Systems Inc. . ----------------------------------------------------------- Permission to use, copy, modify, and distribute these programs and their documentation for any purpose and without fee is hereby granted,provided that the below copyright notice and historical background appear in all copies and that both the copyright notice and historical background and this permission notice appear in supporting documentation, and that the names of MIT, HIS, BULL or BULL HN not be used in advertising or publicity pertaining to distribution of the programs without specific prior written permission. Copyright 1972 by Massachusetts Institute of Technology and Honeywell Information Systems Inc. Copyright 2006 by BULL HN Information Systems Inc. Copyright 2006 by Bull SAS All Rights Reserved