TSM will write data until it hits the physical end of tape.
When you check a tape in, the "estimated capacity" is set by the device
class definition; you can change that to anything you want, reasonable or
not, with UPDATE DEVCLASS.
Regardless, TSM will use the full capacity of the LTO4 cartridge.

If your barcodes and/or the estimated capacity is not right, the only thing
that gets messed up is the "% utilized" of a tape in "filling" status is
less nearly correct. It's never more than a SWAG anyway, for a filling tape,
since TSM can't know ahead of time how much the next chunk of data will be
compressed by the drive.

On Thu, Jul 17, 2008 at 11:07 AM, David Hensley <dhensley AT mcneilusco DOT com>
wrote:

> I have LTO4 tapes with LTO3 barcodes on each tape. When the tapes are
> checked in as scratch TSM sees the size of 1.5gb. When used they go to full
> status with around 800gb on each tape. Compression is turned on. I believe
> this is due to the LTO3 barcodes, since LTO3 compressed tapes are 800gb. I
> need to know if this is the case that TSM is seeing these as LTO3s instead
> of LTO4s. If someone could point me to some documentation I would
> appreciate it. I have tried telling this to my management and they do not
> believe this is so. Thank you.
>
>
>
> Dave Hensley
> Technical Analyst
> McNeilus Companies, Inc.
> Desk: 1-507-374-8587
> Cell: 1-507-244-0921
>
>
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