10/3/89  purge_volume_log

Syntax as a command:  purge_volume_log vlname {-control_args}


Function:  removes, in a consistent manner, those entries in a volume
log that represent out-of-date information.  Each entry in a volume log
is part of a reload group.  A reload group consists of a set of dump
volumes that would be used during a reload of the physical volume.


Arguments:
vlname
   is the name of the volume log.  The volog suffix is assumed if not
   specified.


Control arguments:
-auto
   if specified, the volumes purged are freed in the default dump
   volume pool, which is also known as the tape pool or the volume pool
   segment, and is located at >ddd>volume_backup>Volume_Dumper.volumes.
   For more information, see the description of the manage_volume_pool
   command in the Multics Commands and Active Functions manual, Order
   No.  AG92.  The default is off.
-force
   if specified, causes purging even when some required databases
   cannot be located.


-test
   runs in test mode and reports what would have been done.  No
   databases are affected except for pvolog locks which are reset.
-working_dir, -wd
   specifies that the volume logs are in the working directory, and the
   physical volume logs searched for in the [wd]>pvolog directory.  The
   default is to search relative to the >ddd>volume_backup directory.


Notes: After purging, two reload groups are left in a volume log unless
the number of reload groups has been changed (see the set_volume_log
command).  A reload group consists of the following: all incremental
volume dumps not superseded by consolidated volume dumps; all
incremental and consolidated volume dumps not superseded by a complete
volume dump; a complete volume dump.  By default all consolidated dumps
and those incremental dumps which are not superseded by a complete
dump are retained.  To modify the number of incremental and
consolidated dump sets retained see the -incr_sets and -cons_sets
control argument of the set_volume_log command.


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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