TAPESIZE : Compressed or Uncompressed ??

Hi all, When you set the size of the archive tape device via TAPADEV, do you specify the "commpressed" size or the "uncompressed" size. For eg., our tape drives are said to handle 10G worth of data, but this is compressed data ( from what I was given to understand, the device driver compresses the data before storing it ). Therefore 10G may actually translate to 30-40G uncompressed. How does Informix translate all this. I'm pretty sure that Informix will calculate the size of the backup without any compression factor. My question is: What then should I set the TAPESIZE to. ( By the way, I am using the simple down to earth ONTAPE ) If Informix ( ODS 7.23 UC1 ) prompts you for the second tape based purely on the size in TAPESIZE, and the data is actually compressed, wouldn't it be a better idea to set the tape size to the actual uncompressed size ?? I am going to try out this option today and see the consequences. I guess I would have to do a full restore to see if my backup worked. SLIGHTLY OFF TOPIC: If you had followed my previous chain on a similar topic, "Question on the Archive TAPEDEV size ", of what would happen if we set the tapesize to something much larger than what the tape can hold, then here is what happened. We had set the size to 4 times the actual size ( since that was what the System Admin tool recommended ), and the entire backup fit in one tape ( as opposed to three ) !!! Well, that is what got us wondering on the tapesize itself. We do not know if that backup is actually good. In the meantime, all opinions welcome. Thanks ******************************************************************************** ****************************** * Sujata Soman * * E-Mail: ssoman@omm.com * * Database Administrator ( Informix ) * * O'Melveny & Myers, Los Angeles * ******************************************************************************** ******************************