08/07/86 rebuild_disk

Syntax as a command:  rebuild_disk volume_name drive_name1 -copy
   drive_name2 {-control_args}


Function: rebuilds a disk by copying all information onto another disk
and makes changes to partitions and/or to the VTOC as directed.  You
can use it only in ring 1.


Arguments:
volume_name
   is the name of a mounted physical volume.
drive_name1
   is the source pack's drive in the form <subsys>_<nn>.
drive_name2
   is the target pack's drive to be used for the copy, in the form
   <subsys>_<nn>.


Control arguments:
-console
   sends output to the bootload console instead of to the printer.
-copy
   copies all information from the source pack's drive onto the target
   pack's drive.  (Required)
-debug
   is intended for system programmer use.
-dump
   dumps damaged objects.


Notes: The disk being copied must be in a logical volume that is in
service (has been added to the system with the add_lv command).

This command prints out the current extent and location of partitions
on the source pack, VTOC size, number of VTOC entries, and average
segment length.  The request loop of the init_vol command is then
entered to specify the partition extents and locations of the target
pack and VTOC size.


You can change some of the parameters of a volume, such as VTOC size,
paging region size, and partitions, using rebuild_disk.  Please note:
   1. You can increase the VTOC size, as long as there is room to do
      so.
   2. You can decrease the VTOC size, provided that there are no active
      VTOCEs in the truncated portion of the old VTOC.  The command
      validates this condition and terminates with an error message if
      there are active VTOCEs in the portion of the old VTOC that is to
      be truncated.  You can use the sweep_pv command with -move and
      -from to vacate a portion of the VTOC prior to running
      rebuild_disk.


The disk rebuild operation takes about seven minutes per thousand VTOC
entries in use and one minute per thousand VTOC entries not in use.  A
progress message is reported to the bootload console as every thousand
VTOC entries are processed.

The init_vol request loop assumes the same starting parameters whether
it is being used for a volume initialization or a disk rebuild; you
must not assume that the starting parameters of the target pack are in
any way derived from the source pack.

This command queries you 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.


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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. .

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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