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VCHANGER(8)			 vchanger Manual		     VCHANGER(8)

NAME
     vchanger - Virtual disk-based autochanger for Bacula network backup system

SYNOPSIS
     vchanger [Options] config command [slot] [device] [drive]

     vchanger [Options] config CREATEVOLS mag_ndx count [start]

     vchanger [Options] config LISTMAGS

     vchanger [Options] config REFRESH

DESCRIPTION
     The  vchanger(8)  utility	is  used  to  emulate  and control a virtual au-
     tochanger within the Bacula network backup system environment. Backup  vol-
     umes stored on multiple disk filesystems are mapped to a single set of vir-
     tual slots. This allows an unlimited number of virtual drives and an unlim-
     ited  number of virtual slots spread across an unlimited number of physical
     disk drives to be assigned to a single autochanger. This  allows  unlimited
     scaling of the cirtual autochanger simply by adding additional disk drives.

     Vchanger is primarily deigned for use with removable disk drives. Its abil-
     ity  to  interact	with  Bacula  and determine removable drive mount points
     through udev allow for plug-n-play operation when attaching  and  detaching
     removable disk drives.

     The  first  argument,  config,  is  required  amd specifies the path to the
     vchanger.conf(5) configuration file of the autochanger to be commanded.

     The second argument, command, is the Bacula Autochanger  Interface  command
     to perform.

     The third argument, slot, is required for the LOAD, LOADED, and UNLOAD com-
     mands and gives the slot number of the volume to act upon.

     The  fourth  argument, device, is required for the LOAD, LOADED, and UNLOAD
     commands. It normally specifies the device node of a tape	drive  for  tape
     autochangers.  For vcahnger, it is only required as a place holder, and its
     value is ignored.

     The fifth argument, drive, is required for the  LOAD,  LOADED,  and  UNLOAD
     commands and gives the zero-based drive number to act upon.

     Vchanger  implements  the commands defined by the Bacula Autochanger Inter-
     face specification. The following commands are supported.

     LIST
	 List slots, one line each, in the format slot:label.

     LOAD slot device drive
	 Load the volume in slot slot into drive drive.

     LOADED slot device drive
	 Print the slot number currently loaded into drive drive, or print 0  if
	 the drive is unloaded.

     SLOTS
	 Print the number of slots.

     UNLOAD slot device drive
	 Unload the volume currently loaded in drive drive.

     Vchanger also implements the following undocumented comands

     LISTALL
	 List  drive  status followed by slot status, one line for each drive or
	 slot, in the format type:number:status:label, where type  is  D  for  a
	 drive	or S for a slot, number is the drive or slot number, status is E
	 for empty or F for full, and label is the volume label (barcode).

     Additionally, the following extended commands are supported.

     CREATEVOLS mag_ndx count [start]
	 Create count volume files on the magazine indexed by mag_ndx. Magazines
	 are directories and/or  filesystems  that  have  been	defined  in  the
	 vchanger(5)  configuration  file given by config. The magazine index is
	 based on the order in which the Magazine directives appear in the  con-
	 figuration  file, where index zero is the first occurrence. Optionally,
	 start specifies the minimum integer uniqueness number to  append  to  a
	 prefix  string  when generating filenames for the created volume files.
	 The default is to use a uniqueness number greater than  highest  number
	 currently used for any volume file on the selected magazine.

     LISTMAGS
	 List  the  status  of	all assigned magazines (directories and filesys-
	 tems), one per line, in the format mag:count:start:mnt,  where  mag  is
	 zero-based  index of the magazines specified in configuration file con-
	 fig, count is the number of volume files on that magazine, start is the
	 virtual slot number of the beginning of the range of  slots  mapped  to
	 the magazine's volume files, and mnt is the magazine's directory/mount-
	 point if mounted, or blank if not currently mounted.

     REFRESH
	 Refresh state information for the autochanger defined by the configura-
	 tion  file  config,  issuing  an  update slots command to Bacula if re-
	 quired.

     Bacula Interaction

     By default, vcahgner will invoke bconsole and issue commands to Bacula when
     certain operator actions are needed. When anything happens that changes the
     current set of volume files being used, (the virtual slot	to  volume  file
     mapping),	vchanger will invoke bconsole and issue an update slots command.
     For example, when the operator attaches a removable drive defined as one of
     the changer's magazines, the volume files on the removable  drive	must  be
     mapped  to  virtual  slots.  Since  the  slot-to-volume  mapping  will have
     changed, Bacula will need to be informed of the change via the update slots
     command. The REFRESH command can be invoked to  force  vchanger  to  update
     state info and trigger update slots if needed.

     Additionally,  when  new  volumes	are created with the CREATEVOLS command,
     vchanger will invoke bconsole and issue a label barcodes command  to  allow
     Bacula to write volume labels on the newly created volume files.

COMMAND LINE OPTIONS
     -u, --user=uid
	 Override  the	default user to run as when invoked by root. The default
	 is normally specified in the configuration file given by config.

     -g, --group=gid
	 Override the default group to run as when invoked by root. The  default
	 is normally specified in the configuration file given by config.

     --pool=pool
	 Overrides the name of the pool into which volumes created by the CREAT-
	 EVOLS	command  will be placed when vchanger is configured to label new
	 volumes by sending Bacula a label  barcodes  command.	The  default  is
	 given by the Default Pool setting in the configuration file.

     -l, --label=prefix
	 Overrides the default volume label prefix when generating names for new
	 volume  files	created  by  the  CREATEVOLS  command.	The  default  is
	 name_ndx, where name is the autochanger name and ndx  is  the	magazine
	 index.

     --help
	 Displays command help for the vchanger command.

     --version
	 Displays vchanger version information.

NOTES
     See the vchangerHowto.html file included in the doc directory of the source
     distribution for more detailed documentation.

SEE ALSO
     vchanger.conf(5)

COPYRIGHT
     Copyright 2006-2020 Josh Fisher

     This  is  free software; See the source for copying conditions. There is NO
     warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

AUTHOR
     Josh Fisher <jfisher@jaybus.com>
	 Author.

vchanger 1.0.3			   05/11/2020			     VCHANGER(8)
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