1 VFY
 
 VFY is used to check the consistency of Files-11 volume structure,
 alter the volume structure, or obtain other information about the
 volume.  The general form of the command line is: 
 
	VFY list_file,scratch_device=input_device/switches
 
 The input device must be a disk or DECtape mounted as a Files-11 volume.
 The list_file defaults to TI:, the scratch and input devices default to SY:.
 
	/DE	Undelete any marked-for-delete files
	/DV	Validate directories
	/FR	Display free space on volume
	/ID	Displays the version id number of the VFY task
	/LI	List all index file
	/LO	Scan for lost files and make entry in [1,3]
	/RC	Perform read check
	/RE	Rebuild free storage bit map
	/UP	Update free storage bit map
 
	AID VFY /switch	describes each switch
	AID VFY VFY 		describes the default VFY function 
	AID VFY PERFORMANCE	suggests performance improvements
2 DE
 
	VFY list_file,scratch_device=input_device/DE
 
 This  function  resets  the  marked-for-delete  bit  in each file's file
 header.  The  marked-for-delete  bit  is set when the file system starts
 to  delete  a file, but cannot complete the deletion, usually because of
 a  system  crash.  Such  a file may either be restored (with VFY /DE) or
 deleted with PIP (see main text). 
 
 The  input  device  must  be mounted with the system files unlocked (MCR
 MOU  /UNL).  Write  access  to  the  volume  is necessary.  It is highly
 recommended  that the volume be mounted private, with only VFY operating
 on it. 
 
2 DV
 
	VFY list_file,scratch_device=input_device/DV
 
 VFY  validates  all  the  directories on a volume.  Each directory entry
 presumably  describes  a file;  VFY /DV attempts to match each directory
 entry with the corresponding header in the index file.
 
 See the main text for information on removing invalid directory entries.
 
 The input device may be write locked.  It is recommended that the volume
 be mounted private, with only VFY operating on it. 
 
2 FR
 
	VFY list_file=input_device/FR
 
 The number of free and used blocks on the disk are listed.  PIP /FR also
 performs this function, and lists additional data about the volume.
 
 The input device may be write locked.  It is not necessary for VFY to
 have exclusive access to the volume.
 
2 ID
 
	VFY /ID
 
 Displays the version identification number of the VFY task.
 
 No device or list file is specified.
 
2 LI
 
	VFY list_file=input_device/LI
 
 VFY reports all files listed in the index file.
 
 The input device may be write locked.  It is not necessary for VFY to
 have exclusive access to the volume.
 
2 LO
 
	VFY list_file,scratch_device=input_device/LO
 
 VFY locates all files which are not entered in any directory, and 
 enters them in [1,3].
 
 Write access to the volume is necessary.  It is recommended that the
 volume be mounted private, with only VFY operating on it. 
 
2 PERFORMANCE
 
 VFY performance is generally related to ANSI support and task image size.
 
 It is necessary to rebuild VFY with ANSI support during SYSGEN part 3
 to achieve performance increases for most VFY functions. This is done
 by either rebuilding VFY with [1,1]ANSLIB.OLB, or by rebuilding VFY
 to link to an FCSRES which was build from [1,1]ANSLIB.OLB. 
 
 We also recommend that VFY also be either rebuilt, or installed with an
 increment, to as large a size as is practical on your system. 
 
 Once rebuilt with ANSI support, VFY will use the FCS big buffer feature to
 read files on the input device several blocks at a time. This improves per-
 formance by reducing the amount of head movement on the input device.  Given
 ideal conditions, VFY execution time is roughly proportional to the inverse
 of the size of the block buffer within the VFY task image. "Ideal conditions"
 mean large files (true of the index file, likely less true of directory
 files), a responsive operating system, and minimal contention for the disk. 
 
 Performance of the following VFY functions are not affected by ANSI
 support and task size: 
 
	/ID, /FR
 
 Performance of the following VFY function is affected by task size, but
 not by ANSI support:
 
	/RC
 
 Performance of the following VFY functions are affected by ANSI support
 and task size: 
 
	no switch, /DE, /DV, /HD, /LI, /LO, /RE, /UP
 
2 RC
 
	VFY list_file,scratch_device=input_device/RC:n
 
 VFY attempts to read all blocks of all files on the volume.  The /RC
 parameter "n" is an optional blocking factor.  If it is not specified,
 VFY uses the maximum blocking factor.  If the blocking factor is
 specified, VFY executes the same function, only slower.
 
 The volume may be write-locked.  It is recommended that the volume be
 mounted private, with only VFY operating on it. 
 
2 RE
 
	VFY list_file,scratch_device=input_device/RE
 
 Alter the free storage bit map in accordance with information in the index
 file.  If the default VFY function reports that the "Index indicates X
 blocks free" number is greater than the "Bitmap indicates X blocks free"
 number, VFY /RE will alter the bitmap, freeing more blocks. 
 
 The input device must be mounted with the system files unlocked (MCR MOU
 /UNL).  Write access to the volume is necessary.  It is highly recommended
 that the volume be mounted private, with only VFY operating on it. 
 
2 UP
 
	VFY list_file,scratch_device=input_device/UP
 
 Alter the free storage bit map in accordance with information in the index
 file. If the default VFY function reports that the "Bitmap indicates X blocks
 free" number is greater than the "Index indicates X blocks free" number, VFY
 /UP will alter the bitmap, allocating blocks which actually belong to files.
 
 The input device must be mounted with the system files unlocked (MCR MOU
 /UNL).  Write access to the volume is necessary.  It is highly recommended
 that the volume be mounted private, with only VFY operating on it. 
 
2 VFY
 
	VFY list_file,scratch_device=input_device
 
 The default VFY function: blocks on a volume are counted two ways.  The
 allocation bitmap is a series of bits marked 0 or 1, describing each
 block on the volume as free or allocated in a file.  The index file
 contains file headers which describe the blocks which are contained in
 each file.  VFY counts blocks each of these two ways, reporting the
 counts, as well as noting any blocks allocated to more than one file. 
 
 The volume may be write-locked.  It is recommended that the volume be
 mounted private, with only VFY operating on it. 

