After making a parameter change the server process needs to be restarted. ³³

This is normally done automatically (on the local node only) when you exit from the MEDIAS program after having made a change to a parameter. ³⁴ To restart the server process, you enter the command:

$ @SYS$MANAGER:MEDIA_STARTUP RESTART

In a cluster environment where you made a change to a parameter that affects all nodes, you will need to enter this command on all the nodes involved. The above command procedure requires elevated privileges for execution. Another way of restarting the server is to use the RESTART command. This operation only requires the OPERATOR privilege. To use this command you would enter:

MEDIAS> RESTART

With the above command you could have optionally specified /NEWLOG and the server would restart and open a new log file. ³⁵ All volume and device information is written to disk and then re-read on startup. This means that the restart has very little impact on any on-going operations.

3.3.4 Setting up the MEDIA database

Once you have set up all of the basic parameters the system is ready for immediate use. Now you are ready to add media to the library. You should add blank media to the available pool and active media to the allocated pool. The released pool will form automatically.

The installation procedure set up a queue, by default called SYS$TAPE, designed to be used with TAPE type media. All of the tape drives that you supplied during installation are associated with this queue. SYS$TAPE is left in the STOP state, so you need to manually start it.

To support other types of devices and media types, you need to modify the parameter file. See Section 3.1.1 and Section 3.1.7 for a discussion of TYPE categories and queues and Section 3.3.3 for information about modifying the parameter file.

3.3.4.1 Adding media to the available pool

The available pool is composed of media that are ready to be assigned to users. Add media to the pool by using the following basic command format:

$ MEDIA MEDIUM_NAME ADD/QUALIFIER

If you are using a continuous series of alphanumeric external ID numbers, you can add blank media to the library using the MEDIA ADD command with a range specification in the place of a single medium name:

$ MEDIA B001:10 ADD

This adds in the series of tapes B001, B002, ... B010. The most common qualifiers you will use are:

Qualifier	Description
/LOG	produces a list of all the media affected by the command operation.
/TYPE=word	specifies the type of the added medium.
/LOCATION=word	specifies the location of the medium.
/LENGTH=feet	specifies the length of the added medium.

The /TYPE qualifier should be a specific term, such as REELTAPE, rather than TAPE or DISK, to avoid confusion. Please see the Reference Section for a list of other allowed qualifiers.

For example in your data center you want to use a continuous series of numbers, starting with A001. This will allow you to expand the library as needed up to almost 26,000 media (26 letters in the alphabet times 999 numbers). You are nowhere near that big at the moment, but you want to allow for the possibility of allotting certain series of numbers to specific uses later on. For the moment, to add in the first hundred tapes, you enter:

$ MEDIA A001:100 ADD/LOG

The /LOG qualifier causes a list of the added tapes to be shown on the screen:

$ MEDIA A001:100 ADD/LOG A001 Added A002 Added . . . A100 Added

3.3.4.2 Adding media to the allocated pool

$ MEDIA CATALOG

After entering this commands the system will prompt you for the basic bits of information that are needed to add the medium to the system. Each prompt provides a default value. ³⁷

The default value can be selected by just enter a [RETURN].

For example, you wish to catalog tape B0006 and assign it to the user HOSKINS. The following dialog would take place:

$ MEDIA CATALOG

and the following series of prompts appear:

External label		:	B0006
Internal label	(Blank)	:	<RETURN>
User name	(SMITH)	:	HOSKINS
Comment		:	Daily Transactions
Location	(LIBRARY)	:	<RETURN>
Density	(1600)	:	6250
Protection	(S:RWID,O:RWID,G,W)	:	<RETURN>
Status	(TAPE,LABEL_TBD)	:	<RETURN>
Type	(REELTAPE)	:	<RETURN>
Label	(ANSI)	:	<RETURN>
Mount	(ANSI)	:	Foreign, Nowrite
Update	(ANSI,SDR)	:	<RETURN>
Submit a directory update request [Y/N]		:	YES

The external label is the external markings that are on the tape reel. On this one you have written B0006. If you had several similar tapes and you want to catalog them all together just enter ``B0006,B0123,B0009''.

The internal label is the magnetically encoded label on the tape itself. If you know what the label is enter it here. If you do not know what it is just accept the default and be sure that the STATUS value contains the LABEL_TBD value. This will force the system to make a note of what the internal label is the first time it is mounted.

The user name is the owner of the tape. All entries in the allocated pool are owned by a user. Here just enter the user name of the person who will be responsible for the tape.

The comment is a text field that can contain anything that you feel is useful. It is recommended that you put something here that will help you remember what the tape was for.

The location is the rack or bin in which you will store this tape. This word is sent along with the external id. to the OPERATOR whenever the medium needs to be mounted on a drive. It is usually best to establish some rules for this.

The density is the recording density that the tape was written at. If you do not known what this is, just leave it at the default setting. The system during an update or mount operation will automatically toggle to the correct density setting. ³⁸

The protection setting specifies who can gain access to the tape. In this case the SYSTEM and OWNER have READ, WRITE, INITIALIZE and DELETE access to this tape.

The status field is basic operation control setting. In this example the word TAPE (as opposed to DISK) refers to the fact that the medium is a sequential reel to reel tape. The LABEL_TBD (Label To Be Determined) flag indicates that the tape contains a label but the system does not yet know what it is. Refer to the Reference Section for a complete listing of all the various status flags.

The type word specifies the base TYPE category for this medium. All TYPE's are defined in the parameter file. Earlier, we defined REELTAPE to be magnetic 9 track tapes and CARTRIDGE to be TA90 cartridge tapes. Only values that are already defined can be entered here.

The label field controls how the tape label is checked. The value ANSI indicates that the tape contains a standard VMS tape label. Other possible values are NONE, IBM_SL or DOS. The status flag LABEL_TBD will cause this to be automatically determined the first time the tape is mounted.

The mount value indicates how the tape is to be mounted. This is equivalent to the qualifiers that can be used with the VMS MOUNT command. Possible values are ANSI for a normal VMS mount, FOREIGN for a nonVMS tape or READONLY for reels that should never be written to.

The update value controls how the on-line contents file is updated whenever data is added to the tape. Typical values are "ANSI,SDR" for tapes created by the VMS COPY command, "NONE,SDR" for tapes that you do not want contents information on-line, or NONE,BJL for BACKUP tapes where the journal files are inserted independently.

An update request can be created by answering YES to this last question. What this creates is a MEDIA batch job ³⁹

that will request the OPERATOR to mount the tape on a drive and then update the on-line database with what files are found on the tape.

3.3.4.3 Incorporating existing information

If prior to installing MEDIA , you have been keeping tape directory listing files, backup journal files, backup listing files or any similar file on-line to facilitate locating where a file is, these can easily be added into the MEDIA database. The MEDIA CONVERT command is the general purpose tool for reading log files or listing files. The MEDIA APPEND_JOURNAL command will read in backup journal files.

If you do not have any files on-line that contain information about what is on your existing tapes or disks, then you can use the MEDIA UPDATE command. This command will read the file headers on the medium and add that information to the MEDIA database.

For example, you have a tape that was created using VMS copy (i.e. an ANSI tape) and you have on-line a directory listing ⁴⁰ of that tape. To add this tape into the allocated pool and then add in the listing file you would enter the following commands:

$ MEDIA A1245 ADD/USER=SMITH/TYPE=REELTAPE/DENSITY=6250 - /STATUS=(TAPE,LABEL_TBD) $ MEDIA A1245 CONVERT/UPDATE=(ANSI,TDR) MYLISTING.DAT

For example, you have a tape that was written by VMS BACKUP and you have saved the journal file. ⁴¹ To add this tape into the allocated pool and then add in the journal file you would enter the following commands:

$ MEDIA A1245 ADD/USER=SMITH/TYPE=REELTAPE/DENSITY=6250 - /status=(tape,label_tbd) $ MEDIA A1245 APPEND_JOURNAL MYJOURNAL.BJL

For example, you have a tape created using the VMS COPY command but you do not have any directory listings of that medium. In this case you can use the CATALOG command described in the previous section to add the tape to the database and create an UPDATE job to read in the contents information. Alternately you could use the following commands:

$ MEDIA A1245 ADD/USER=SMITH/TYPE=REELTAPE/DENSITY=6250 - /STATUS=(TAPE,LABEL_TBD)/UPDATE=(ANSI,SDR) $ MEDIA A1245 SUBMIT_UPDATE

The ANSI update operation maintains on-line the same information that the VMS DIRECTORY command could return about the tape. If data had been written to the tape by VMS BACKUP then the ANSI update routine will return the names and sizes of the various savesets (not the contents of the saveset) on the tape.

For example, you have a tape that was written by VMS BACKUP but you do not have a journal or listing file of the files that where put into the saveset. The information that you want in the database is the contents of the saveset, not the description of the saveset itself. To do this you will need to use the following commands:

$ MEDIA A1245 ADD/USER=SMITH/TYPE=REELTAPE/DENSITY=6250 - /STATUS=(TAPE,LABEL_TBD)/MOUNT=(FOREIGN,READONLY) $ MEDIA A1245 * MEDIA $ BACKUP MEDIA:/LIST=TEMP.LIS MEDIA $ MEDIA 'MEDIA_EXT' CONVERT/UPDATE=(NONE,TDR) TEMP.LIS MEDIA $ <CTRL/Z>

The above commands could have been put into a COM procedure instead of being entered in full as in the above example.

3.4 Other features

There are several other useful features that are available to simplify your removable media handling problems. These are discussed in the following sections.

3.4.1 Device control

To increase security, all removable media drives can be allocated to the MEDIA server process. The server process will only turn over control of these devices to proper requests issued via the MEDIA command. This feature is enabled by setting the parameter file variable LOCK_DEVICES equal to 1. Please refer to a later chapter for more details about the parameter file. This prevents the execution of a VMS ALLOCATE command. Only a MEDIA ALLOCATE command will give access to the device.

The parameter INTERACTIVE controls whether device commands can be executed interactively. By inhibiting interactive operation of these commands, the user is forced to create a batch job either on his own or via available job commands. Once submitted, the actual time that a media job is executed is controlled by the OPERATOR.