Tapes get marked "full" when ADSM hits the end of volume.  If you are
getting media errors, this could happen prematurely.


They are COMPACT IV tapes?  It is a DLT 7000 drive?  (DLT 4000 are
20GB native, 40GB "typical compression")



Manually load a tape and look very carefully at the density lights on
the DLT drive.

DLT tapes can do 35GB, but for backwards compatibility they can do
lower densities.

The drive decides on the density when the tape is first written to and
that density is used forever more.

It is possible to "reformat" the media to a higher denisty:

0.  Make sure there is no ADSM data on the tape and the volume has been
    deleted from the library and adsm volume list
    Mark the drive as "offline" in ADSM
1.  Mount the tape manually in the drive
2.  Use the "density select" button to choose 35GB
3.  At the UNIX system
        dd if=/dev/zero of=/dev/rmt/X count=100
    (/dev/rmt/X is the real OS device driver for the drive)
4.  Unmount the tape
5.  Mark the drive as online
6.  Get ADSM to relabel the tape


This works because the DLT drive will change the media density IF it
is writing at the beginning of the tape.

I did this repeatedly when we moved tapes that were used in a DLT 4000
drive to a DLT7000 library.


I am getting > 35GB on my DLT tapes.


Hope this is of some help

Russell




> hi adsmers,
>
> is there anyone out the experienced the same thing: i just noticed that
> sometimes adsm changes a filling tape to status full even tho' the tape
> still got plennnnnnnty of room to put data in. to be more specific, before
> i did a "move data dlt009" i had:
>
>
>
> adsm> q vol dlt*
>
> Volume Name                  Storage         Device         Estimated     
> %Util      Volume
>                              Pool Name       Class Name      Capacity         
>        Status
>                                                                  (MB)
> ------------------------     -----------     ----------     ---------     
> -----     --------
> DLT001                       DLT-LIBRARY     DLT-AUTO        27,578.4      
> 58.8       Full
> ...
> DLT007                       DLT-LIBRARY     DLT-AUTO        35,840.0      
> 50.9     Filling
> DLT008                       DLT-LIBRARY     DLT-AUTO        35,840.0       
> 6.7     Filling
> DLT009                       DLT-LIBRARY     DLT-AUTO        35,840.0       
> 3.8     Filling
> ...
>
>
>
> it then moved data off dlt009 to dlt007. but now i have:
>
>
>
> adsm> q vol dlt*
>
> Volume Name                  Storage         Device         Estimated     
> %Util      Volume
>                              Pool Name       Class Name      Capacity         
>        Status
>                                                                  (MB)
> ------------------------     -----------     ----------     ---------     
> -----     --------
> DLT001                       DLT-LIBRARY     DLT-AUTO        27,578.4      
> 58.8       Full
> ...
> DLT007                       DLT-LIBRARY     DLT-AUTO        30,399.7      
> 64.2       Full
> DLT008                       DLT-LIBRARY     DLT-AUTO        35,840.0       
> 7.4     Filling
> DLT009                       DLT-LIBRARY     DLT-AUTO             0.0       
> 0.0      Empty
> ...
>
>
>
> also, i don't seemed to be able to utilize the whole tape, the estimated
> full capacity is 35G but it got marked full somewhere around 30G. my
> devclass of dlt's definition is -format=drive.
>
>
> thanks.
>
>
>
> yu chen
>
>
>
>
> -- The Lost Patrol. Level 30~36, HP 800, AC -2. The Highway Patrol of
>    The Random Road, They Keep The Peace, They Eat Donuts.    -TRR '97