Automatic free tape allocation

The MAREN component MARENUCP automates the allocation of free tapes.

If a tape is requested in BS2000 without specifying an archive number (scratch request), the MARENUCP automatic free tape allocation facility selects a free tape, assigns it to the requester, and marks it as reserved in the MAREN catalog.

In the event of a corresponding request, MARENUCP requests the operator to mount a tape (VSN proposal). The operator can mount the proposed tape or a different free tape, which is then automatically allocated.

If a tape output file is to be created, a tape is automatically assigned in the following cases:

• In the CREATE-FILE or CREATE-FILE-GENERATION command, the operand VOLUME=*NO (default value) or *ANY is used in conjunction with SUPPORT=*TAPE;
• When using the ARCHIVE statement SAVE or EXPORT, TAPES=OPERATOR or TAPES=POOL is specified, and there are no more free tapes available in the ARCHIVE directory.

The MAREN administrator has the task of creating and managing the automatic free tape allocation. This is described in the “MAREN System Administrator Guide” [1].

Further processing of archive numbers

Each archive number reserved by MARENUCP can be stored in a job variable. 

This function is activated when the MAREN user issues the SET-JV-LINK command to assign the link name MARENJV to any job variable or sets up a job variable with the name <filename>.MAREN, <filename>.<jobname> or <filename>.M<tsn>.

Thereby <filename> is the name of the relevant output file, <tsn> is the TSN and <jobname> is the job name or HSMS request name of the user task. If several such job variables exist, only one is set. A job variable assigned using the link name has the highest priority. Then come the variants with the extensions .M<tsn>, .<jobname> and .MAREN.

If the file name includes a generation number or a version ID, this must be omitted (including parentheses). This permits separate follow-on processing of archive numbers from several output files.

In the case of a multivolume file, a list of VSNs (<vsn1>,<vsn2>,...) is created dynamically in the job variable and extended by one entry for each further output tape. A maximum of 36 archive numbers per job variable is possible.

When evaluating a job variable, please note that a job variable already containing a VSN will be extended dynamically to form a VSN list each time the free tape allocation facility is used.

The neatest method of follow-on processing takes place indirectly via SDF, where a job variable is specified in place of part of a command or statement.

The follow-on processing of a VSN is also supported by the following components:

• The name of the HSMS/ARCHIVE directory must be specified for <filename> in the case of HSMS or ARCHIVE applications with a directory file;
• The name “ARCHIVE.SAVE.FILE” is used for <filename> in the case of ARCHIVE applications without a directory file.

Restriction

In HSMS and ARCHIVE the job variables cannot be assigned by means of the link name. Furthermore, the name variant with the extension .M<tsn> is not supported.

Example 1

In the task with the job name BACKUP, an ARCHIVE backup is to be carried out with the directory file TAPE.DIR. Tapes are requested by means of automatic free tape allocation.

/set-logon-parameters .. user-identification=userxy01,...,job-name=backup
...
/show-jv-attr tape.dir.
%0000000 :2OSG:$USERXY01.TAPE.DIR.MAREN
%0000000 :2OSG:$USERXY01.TAPE.DIR.BACKUP
%SUM    00002 JV'S; JV-VALUE = 00000000 BYTES
/start-archive
%  ARC0001 ARCHIVE READY
* f na=database.evaluation.0499
* save directory=tape.dir,tapes=operator,device=tape-c4
%  ARC0002 STATEMENT ACCEPTED. ARCHIVE SEQUENCE NUMBER 'A.990510.171336',VERSION
'<version>'
%  ARC0033 ARCHIVE SUBTASK TSN '04AS' GENERATED
%  ARC0003 ARCHIVE STATEMENT COMPLETED
* end
%  ARC0009 ARCHIVE TERMINATED
/show-jv-attr tape.dir
%0000000 :2OSG:$USERXY01.TAPE.DIR.MAREN
%0000006 :2OSG:$USERXY01.TAPE.DIR.BACKUP
%  ARC0003 ARCHIVE STATEMENT COMPLETED
%SUM    00002 JV'S; JV-VALUE = 00000006 BYTES
/show-jv tap
%M5660K

Example 2

An output tape allocated by MARENUCP is to be created. The reservation period is to be set to 60 days in the corresponding MAREN archive entry. The tape (with the VSN TC1001 in the example) is then to be sent.

...
/start-maren
/create-jv jv-name=tape.file.jv
/set-jv-link link-name=marenjv,jv-name=tape.file.jv
/create-file file-name=tape.file,supp=tape(vol=*no,dev-type=tape-c4)
/add-file-link link-name=...,file-name=tape.file
/start-prog from-file=...
...
/show-jv jv=tape.file.jv
%TC1001
//modify-vol-attr vol=&(*marenjv),protection=par(free-date=60)
%MARM121 MAREN CATALOG ENTRY 'TC1001'/'0001' MODIFIED
//export-vol vol=&(*marenjv),export-addr='Hamburg'
%MARM134 GET VOLUME 'TC1001' FROM CENTRAL ARCHIVE
%MARM170 STATEMENT 'EXPORT-VOLUME' PROCESSED
//end
%MARM098 MAREN TERMINATED NORMALLY
/export-file file=name(file-name=tape.file)
/del-jv jv-name=tape.file.jv
...