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:. Legal switches are: (no switch) Default function: check validity of the volume /DE Undelete any marked-for-delete files /DV Validate directories /FR Display free space on volume /HD Delete bad file headers, prompting for action -->/AL Subswitch for /HD - delete all bad headers, no prompt /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 Additional information is available: HELP VFY /switch describes each switch HELP VFY VFY describes the default VFY function HELP VFY PERFORMANCE suggests performance improvements 2 AL #HD 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 HD VFY list_file,scratch_device=input_device/HD VFY scans the system files for validity. When a bad file header is encountered, VFY prompts for action. See the main text for the specific choices at this point. Subswitch /AL supresses the prompt; VFY /HD/AL will automatically delete all bad headers. 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 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.