Using Virtual Tape to Save Data

IBM i includes Virtual Tape Save, which provides more flexibility for your save strategies. The virtual tape save is built on IBM's Image Catalog technology. It uses virtual storage to create a virtual tape images that reside on your hard disk. Once the virtual tape image is populated, you can use the DUPTAP command to save your data to physical media, such as tape.

To use a virtual tape save, you must define a virtual tape device that you then can specify in your backup command just as you would any other device.

Creating a Virtual Tape Device

  1. Enter the following command to create the virtual tape device (you only need to do this once):

    CRTDEVTAP DEVD(TAPVRT01) RSRCNAME(*VRT) TEXT('Virtual Tape Device')

  2. Enter the following command to vary on the device:

    VRYCFG CFGOBJ(TAPVRT01) CFGTYPE(*DEV) STATUS(*ON)

  3. Enter the following command to create the image catalog for the save:

    CRTIMGCLG IMGCLG(catalog_name) DIR('/IMAGECATALOG') TYPE(*TAP) TEXT('Save Image Catalog')

    where catalog_name is the name of the image catalog you are creating.

    Note: You can use this image catalog multiple times.

  4. Enter the following command to create virtual tape volumes for your backup:

    ADDIMGCLGE IMGCLG(catalog_name) FROMFILE(*NEW) TOFILE(VOL001) VOLNAM(VOL001) DENSITY(*VRT32K) NEWOWNID(user1)

    where catalog_name is the name of the image catalog and user1 is the owner of the virtual tape cartridges.

    Repeat this command as many times as necessary, changing the TOFILE and VOLNAM parameter, to create enough virtual volumes as you need.

  5. Enter the following command to load the image catalog to the virtual tape device:

    LODIMGCLG IMGCLG(catalog_name) DEV(TAPVRT01) OPTION(*LOAD)

After you complete these steps, you can specify the virtual device you created in Step 1 as the device in all your Robot Save backups.

Special Notes

  • You can write-protect image catalog entries using the CHGIMGLE command.

  • There can be a maximum of 35 virtual tape devices defined to your system.

  • You can secure a virtual image by giving it a digital signature.

  • You can use a virtual tape device for all save commands that can be executed to physical media except for the following:

    • SAVSTG

    • Dump to media from SST and DST

  • The minimum size for a tape image file volume is 48 MB; the maximum size is 1,000,000 MB.

  • Files can span virtual volumes, just like physical volumes. If you specify *MOUNTED on your command, the volume that is mounted will be used. If no volumes are mounted, the next loaded volume will be mounted automatically.

  • If you specify *MOUNTED for a save, a new volume will be created automatically when the save reaches the end of the defined image catalog volumes.