Vtape pools range
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Vtape pools range


Article ID: 218597


Updated On:


Vtape Virtual Tape System



We are nearing the limit on the size of our Vtape pool. I was wondering what the limit is we can define? Can I go up up 999999 volumes? 

Also, if I want to create a second pool, do I define volumes in Pool2 like our current one, and can the same range be defined in both?

SVT1X1417I Volume Pool Range Display
Pool#      VolSz     #Vols       #Scr    Volser-Range
------        ------       -------       -------   -----------------------------------------
POOL1  16000M  600000   13710  000000-010000 200000-2100000
--------                   ------         -------   ------- -----------------------------------------
Totals                   600000    13710



Release : 12.6

Component : CA VTAPE




Concerning the various questions for adding more virtual volumes for Vtape:

1) You can go up to 1,000,000 virtuals per Vtape complex (if you have 8 Vtapes - SVT1 to SVT8 - sharing the same global VCAT, then these 8 Vtape systems would have to 'share' the total 1,000,000 volumes).

2) You can NOT overlap Vtape volume ranges amongst the different pools.  If you do, you will get an error either when Vtape is started, or when you issue a SVTn REFRESH=POOLS command.  

As an additional note concerning the Vtape pool definitions (member VTPOOL), each pool range value (i.e., starting volume and ending volume number/name) must begin with the same 'prefix' character.  For example:

VolserRange = 100000-199999   *** valid

VolserRange = V00000-V99999  *** valid

VolserRange = 100000-299999   *** invalid  

Concerning the EXPAND Vtape job which is used to expand the VCATs when volumes are added, to add an extra 400,000 volumes to the current 600,000 volumes, giving you 1,000,000 volumes total, the following control cards would be used in the IDCAMS and SVTSUTIL jobsteps, respectively, of the EXPAND job: 

RECORDS ( #OFVVOLS+45824+2 1 )  -->  RECORDS ( 600000+45824+2   1)  -->   ( 645826  1)

EXPAND CDS,VOLUMES=400000    *** no need to specify the CONVERT parm here, as the VCATs have already passed this hurdle in going to 600,000 volumes earlier.

Now, concerning using an existing '800000' volser range which is already being used for *real* tapes, this range would be 'off limits' for use by Vtape.  
The tape volsers assigned to Vtape would only be for virtual volumes - mixing real and virtual tape volsers together is not allowed.  
Concerning the 1,000,000 volume limit for number of virtual volsers, this limit applies to the *entire Vtape complex*, so this is the maximum number of volumes that can be defined across all Vtapes that share the same Global VCAT, and this is regardless of whether one huge volume pool is specified, or many smaller pools are defined and spread across potentially up to 8 separate Vtape instances.  
This isn't all bad, as the Vtape RECYCLE utility can be used to reclaim older volumes for which data has expired, thus freeing up new tapes for scratch.

Additional Information

See the section: Increased Virtual Volume Capacity



RECYCLE utility: