Directory Program Allocating DASD Space for the VM/370 Directory
Before you create your VM/370 directory using the Directory program, be
sure you have enough DASD space allocated as directory space (DRCT). Use the CP Format/Allocate service program to format and allocate the
cylinders to be used for the VM/370 directory. The cylinders must be
allocated as DRCT. To calculate the total number of cylinders required,
first calculate the total number of records used: NU «NU + NM) x 2) + all other control statements
NR =
+ ----------------------------------------------
169 170 NR = total number of records used NU = number of USER control statements NM = number of MDISK control statements (except for temporary
disks)
Then, calculate the number of cylinders (NC): • For 3330: NC = NR/57 • For 2314,2319: NC = NR/32 • For 2305, 3340: NC = NR/24 • For 3350: NC = NR/120 You should initially format and allocate space for two VM/310 directories. You can then build a new directory whenever needed,
without overlapping the current one, and without formatting and
allocating space each time a new directory is created. If you wish to
reallocate the area in which the directory resides, you must reallocate
the DASD space and then rerun the Directory program. When a VM/310 directory is written, space is allocated from available cylinders, a
full cylinder at a time, and a minimum of two cylinders are used for the VM/370 directory.
Once a new VM/370 directory is successfully written, cylinders used
for the old directory (marked as temporarily allocated during directory
creation) are marked as free. In this way, DASD space allocated for DRCT
cylinders is freed and can be reused for the next directory creation.
If space for two directories is not initially allocated, each time you
want to create a new directory, you must allocate space for the
directory before you create it.
196 IBM VM/370 Planning and System Generation Guide

Directory Program
The Directory Program
The directory program can be run under CMS (using the DIRECT
command) or standalone. The standalone version of the directory program
is provided in object deck form (a three card loader, followed by the DMKDIR text deck), and may be loaded directly from either a real or
virtual card reader.
If you run the directory program under CMS, input records must be in
a CMS file with a default fileid of "USER DIRECT". The DIRECT command
loads the directory creation module. If no filename is specified, the
program looks for a file named USER DIRECT. Otherwise, it looks for a
file named filename DIRECT.
If the file is not found, or if an error occurs during processing, the directory is not created and the old directory remains unaltered. Normal completion writes the DASD address of the new VM/370 directory
in the VOLl label, and if it is updating the active system directory, it
places the new directory in use by VM/370. You can print the new
directory by issuing the CMS command PRINT USER DIRECT (or PRINT filename DIRECT).
The virtual machine executing the directory program must have write
access to the volume to contain the new directory. If you create a
directory that is to be written on the active VM/370 system residence
volume, your virtual machine's current directory entry must have write
access to the volume containing the current VM/370 directory. Assume that you have the following virtual machine for online
directory modification. USER UPDRCT PASSWORD 256K 1M ABC ACCOUNT NUMBER BIN2 IPL CONSOLE 009 3215 SPOOL C 2540 READER A SPOOL D 2540 PUNCH A SPOOL E 1403 A
LINK CMSSYS 190 190 R MDISK 330 3330 o 404 SYSRES MDISK 331 3330 o 404 SYSWRK MDISK 230 2314 o 203 UDISK 1 MDISK 231 2314 o 203 UDISK2 MDISK 232 2314 o 203 BATCH1 MDISK 233 2314 o 203 BATCH2 MDISK 191 3330 26 0110 VMDSK2 WR RPASS WPASS WR RPASS WPASS RR RPASS WPASS RR RPASS WPASS RR RPASS WPASS RR RPASS WPASS WR RPASS WPASS Using the CMS EDIT command and its subcommands, you can create or
modify a card-image file of the VM/370 directory input. When you are
ready to write a new directory, issue the command:
DIRECT filename
where filename is a CMS file (normally named USER) with filetype DIRECT
containing the necessary Directory program control statements. The
DIRECT command puts this file into the form of a directory, and replaces
the old directory with this new one. Part 2. Defining Your VM/370 System 197