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raak
Active User
Joined: 23 May 2006 Posts: 166 Location: chennai
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Hi,
In our system, we are using Unit=VTAPE for using Tape files. What does that V inVTAPE stand for? What is the purpose of it? is it different from ordinary tapes?
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chtrisa
New User
Joined: 19 Dec 2006 Posts: 12 Location: chennai
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hi Raak,
VTAPE or V-Tape stands for Virtual Tape. This is a way to keep part of an organization's "tape" inventory on disk.
Many jobs have "tape" DD statements that would be better served if they were not on a physical reel/cart. V-Tape intercepts "tape" i/o for those files defined to the V-Tape system.
One choice would be to redo all of the jcl, but that is often too costly to do. Using V-Tape, all of the original jcl works as is and the switch is all done internally.
When you use V-Tape, a new series of "tape volumes" is defined to the V-Tape system and to the tape management system. These virtual tapes are processed just like the plastic ones.
Hi chtrisa - the posted link gets a 404 error
Quote: |
We're sorry.
We have recently updated our Web site and the page you are looking for no longer exists. Please consult the site map below to find what you are looking for or contact us if you have any additional questions.
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Lance Revell
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Joined: 04 Feb 2007 Posts: 1 Location: Tallahassee, Florida USA
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This depends on the particular data center too. At mine, we use "TAPEC" for cartidges, but the volume serial determines whether a physical tape or a virtual tape. A five digit volser is a physical tape, while a six digit volser is automatically a virtual tape. Both are cataloged and function identically in the JCL. |
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dick scherrer
Moderator Emeritus
Joined: 23 Nov 2006 Posts: 19244 Location: Inside the Matrix
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Hello,
If your site adds a new generic for virtual tape it may be something like VTAPE.
You may not want to change all of your existing jcl to point to the new VTAPE. The virtual tape system is told which datasets are to be mounted on virtual tape drives which means existing jcl will work as is.
As Lance pointed out, they use TAPEC - the tape management system along with the virtual tape system know which pool of "tapes" to use. The physical tapes and the virtual tapes have separate tape pools. Again, as they do where Lance is - the pools should have unique and easily identified series of volsers. |
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chtrisa
New User
Joined: 19 Dec 2006 Posts: 12 Location: chennai
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sorry....i attached that pdf... |
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