5.3 Making Disk Services Available Using the Command
Line
Virtual disks, which are stored on the server, provide fast
access to DOS files. You make virtual disks available to
users by mounting them. A mounted virtual disk is a disk
service .
You can use the command line instead of the menu to
make virtual disks available to users. Use the command
line when you want to:
A personal disk service gives users quick access to
personal files. A disk service is well suited for personal use
because only one user can read from and write to it at the
same time.
To make disk services available to users, you need to:
5.3.1 Creating Virtual Disks
When you create a virtual disk, you define its location and
space allocation.
Defining a Location
Think about the location of virtual disks to help you
organize them. You can organize directories for specific
uses and store virtual disks in the appropriate directory.
Or, you may want to organize virtual disks on different
devices to evenly distribute requests for them.
You create a virtual disk in either default or explicit
locations.
Using Default Locations
The server provides logicals that define default locations
for virtual disks. To create a virtual disk in the default
locations, use the /TYPE qualifier in the CREATE
command.
Using default location for
virtual disk
Table 5-1 shows each service type and the default directory
for each type.
The default service type is USER. For example, to create a
virtual disk in your default VMS directory, use the default
/TYPE qualifier, as follows:
PCSA_MANAGER > CREATE DISK MYSERVICE
Use the /TYPE qualifier
to create the disk in
the default application
directory.
To create an application virtual disk in the default location
for application disks, use the /TYPE qualifier as follows:
PCSA_MANAGER > CREATE DISK MYAPP /TYPE=APP
The disk MYAPP.DSK is stored in the LAD$APPLICATION_
DISKS directory.
When you mount the disk, use the same /TYPE qualifier
that you use in the CREATE command.
Using Explicit Locations
You can also create the virtual disk the directory you
specify. Specifying the directory overrides the value used
with the /TYPE qualifier.
Creating a virtual disk in
a specific directory
For example, to create a virtual disk MYDISK for User1's
personal use in the directory DUA0:[USER1], enter the
command:
PCSA_MANAGER> CREATE DISK DUA0:[USER1]MYDISK
Make sure you have read and write access to the VMS
directory you specify.
Limiting Virtual Disk Space
When you create a virtual disk, you define its size and its
initial allocation. The size of the virtual disk is a maximum
limit that the disk can ever occupy. The allocation limits
the space initially allocated when you create the disk.
When you create a virtual disk, the disk is formatted for
the size you specify. By default, the disk allocation equals its
full size.
To conserve disk space, reduce the allocation by setting it
between the minimum and maximum values shown in
Table 5-2. Table 5-2 shows the disk sizes you can use and
the allocation allowed for each size.
To use more disk space than you initially allocated, you
need to extend the disk size (see Section 5.4.5).
Note: To access virtual disks larger than 32 MB, users
need to use DOS V4.0 or later.
For example, to allocate only 1800 blocks of the 1.44 MB
reserved in the following command, enter:
PCSA_MANAGER> CREATE DISK DUA0:[USER1]USER1 /SIZE=1.44 /ALLOCATION=1800
5.3.2 Mounting Virtual Disks
After you create the virtual disk, make it available by
mounting it. Once mounted, the disk is available to users as
a disk service .
Mount a disk to make it
available to clients.
When you mount a virtual disk, you can:
When you mount a virtual disk, its default location is
defined by the /TYPE qualifier (see Section 5.3.1.)
Defining Access
Default = 30 users
When you mount a virtual disk from the command line,
by default, 30 users can read from the disk service but not
write to it.
To mount a virtual disk with read and write access for one
user, enter:
PCSA_MANAGER> MOUNT DISK MYSERVICE /ACCESS=WRITE /TYPE=APP
Assigning a Password
To assign a disk service password, use the MOUNT
command.
Use the /PASSWORD
qualifier to ensure
security.
For example, to mount the virtual disk USER1.DSK with a
password NOENTRY, enter the following command:
PCSA_MANAGER> MOUNT DISK USER1.DSK /PASSWORD=NOENTRY
Limiting Connections to Read-Only Services
To ensure security, limit the connections to read-only
services. (Write access is automatically limited to one user.)
Ensure security by limiting
connections to a disk
service.
For example, to limit the connections to the disk service
MYSERVICE to 3, enter:
PCSA_MANAGER> MOUNT DISK MYSERVICE /CONNECTIONS=3
Making a Disk Available Temporary or Permanently
You mount a disk either temporarily or permanently.
Mount disks temporarily for short-term storage. Temporary
disks are mounted as long as the disk server keeps running.
Permanent disks are mounted each time the server reboots.
Use the /PERMANENT
qualifier for permanent
mount.
By default, a virtual disk is mounted temporarily.