Technical data

Managing Storage Media
9.5 Mounting Volumes
You can check that the volume is ODS-2 by entering a SHOW DEVICE/FULL
command and seeing a display like the following:
$ SHOW DEVICE DKA200:/FULL
Disk $10$DKA200:, device type RZ47, is online, allocated, deallocate
on dismount, mounted, file-oriented device, shareable.
Error count 0 Operations completed 232
.
.
.
Volume Status: ODS-2, subject to mount verification, file high-water
marking, write-back caching enabled.
An alternative method for displaying the volume type is to issue a command
and receive a response similar to the following:
$ WRITE SYS$OUTPUT F$GETDVI ("DKA200:","ACPTYPE")
F11V2
F11V2 indicates that the volume is ODS-2.
3. Compaq strongly recommends that you back up the volume. You cannot go
back to ODS-2 format once you change to ODS-5 except by restoring a backup,
as described in Section 9.5.5.3. For example:
$ BACKUP /IMAGE DKA300: SAV.BCK /SAVE_SET
4. Set the characteristics of the disk by using a command in the following
format:
SET VOLUME /STRUCTURE_LEVEL=5 device-name
For example:
$ SET VOLUME /STRUCTURE_LEVEL=5 DKA300:
Note
You cannot use the SET VOLUME command to change a volume from
ODS-5 to ODS-2. To reset a volume to ODS-2, you must use BACKUP as
described in Section 9.5.5.3.
If a failure occurs after you enter the SET VOLUME/STRUCTURE_
LEVEL command, refer to the instructions at the end of this section.
When you enter the SET VOLUME command, the system verifies that the
volume can be converted by testing for the following items:
• The device must be a disk, and its on-disk structure must be ODS-2 or
ODS-5.
If the volume fails these tests, the system displays messages similar to
the following:
%SET-E-NOTMOD, DKA300: not modified
-SET-E-NOTDISK, device must be a Files-ll format disk
%SET-E-NOTMOD, DKA300: not modified
-SET-W-INVODSLVL, Invalid on-disk structure level
• The disk must be privately owned; the owner process-ID (PID) must be
the same as the PID of the parent process that issues the SET VOLUME
command.
Managing Storage Media 9–37