Map VTOC entries in pack location sequence (M)

The Map VTOC entries in pack location sequence function (option M) shows a physical display list of all contents on the volume. In addition to the data sets and their extents, option M also displays the VTOC, its pointer, and lost or free space.

Because this option displays information by its physical sequence on a volume, it can only display entries of a single disk pack.

Enter an M in the OPTION field and specify a single volume number in the Volume serial field on the VTOC Utility screen. When you press Enter, File-AID displays the physical structure of the disk pack on the Utility VTOC List screen as shown in the following figure.

To process a generic search and display the physical structure of a disk pack, specify a search name on the VTOC Utility screen. Then, only the data sets matching the search mask (pattern dataset name) are listed on the Utility VTOC List screen.

Utility VTOC List Screen - Volume-Location Sequence

Utility VTOC List Screen - Volume-Location Sequence for EAV DASD

The top line of the Utility VTOC List screen displays the disk pack name with the type (in parentheses), and the number of data sets in the list.

When Display Volume Summary is set to Y, the volume summary information is displayed in the following lines, beginning with the headings: VTOC, VOL, and FREE. A fourth volume information line is displayed if a generic search is specified.

The next four lines only display for EAV DASD and show track- and cylinder-managed free space information.

If the Search dataset name field was specified, the displayed list matches the specified name. The data set list area is organized in columns. Field Descriptions describes the information displayed on the screen. If no dataset name matched the specified name, File-AID displays the message: NO DATASET FOUND in the upper-right corner of the VTOC Utility screen.

Overlapping Extents and Lost Space

The File-AID VTOC utility allows you to map a DASD device online showing the data sets and free space extents in ascending CCC-HH order. Look at this information as a snapshot of the device’s VTOC; that is, a picture of the VTOC at the time File-AID processes it. File-AID processes the VTOC without issuing enques while collecting the extent information.

After collating the extents into ascending order, File-AID formats the display table and checks for LOST SPACE. The next data set/free space extent location is checked against the last data set/free space ending location and File-AID notes any extent overlaps (OVERLAPPING EXTENTS) or gaps (LOST SPACE).

An area on a disk pack is considered "lost" when it is unaccounted for in the VTOC. This area physically exists, but is not recognized by the VTOC as belonging to a file or free space. The File-AID VTOC Utility recognizes this condition and flags it as lost space with the message: * * * L O S T S P A C E * * * in the DATASET NAME area of the Utility VTOC List screen. When this message is displayed, specify FIND L O S T in the COMMAND field and press Enter. File-AID positions the display to the first lost space area. The following figure shows you this display.

Utility VTOC List Screen for Lost Space and Free Space

When a lost space area is displayed on the Utility VTOC List screen, the STATUS column displays the message: >UNACT to indicate that this area on the disk pack is currently unaccounted for.

You can find free space entries by entering: FIND F R E E in the COMMAND field of the Utility VTOC List screen.

Enter the RFIND command to scroll the display to the next free space area.

If required, scroll down the data set list to the desired data set. VTOC Utility Line Commands lists the line commands that you can enter on a list of data set names.

Press END (PF3) to return to the VTOC Utility screen.

Example

Search volume TSOI01 for the location and extents of all data sets on the volume with names ending with SOURCE. Only data sets that match the search dataset name mask value are shown.

Enter M in the OPTION field, TSOI01 in the Volume serial field, and +.SOURCE in the Search dataset name field on the VTOC Utility screen.

When you press Enter, File-AID scans the indicated disk pack VTOC and lists only the dataset names with SOURCE as a suffix on the Utility VTOC List screen as shown in the following figure.

Utility VTOC List Screen for Source Datasets - Volume-Location Sequence

The format of the display is the same as that of a non-generic search. However, the list now shown is a partial list of the disk pack. Notice that the DATASET NAME field is shown and the list does not indicate free space. Press END (PF3) to return to the VTOC Utility screen.