Hi managers :
First to all :
Thanks to
Peter Reynolds [PReynolds_at_synstar.com]
Shane Feeney [shane_at_bcn.com.au]
Tom Webster [webster_at_ssdpdc.lgb.cal.boeing.com]
Mervyn Weis [Mervyn.Weis_at_digital.com]
John Francini [francini_at_nashua.progress.com]
alan_at_nabeth.cxo.dec.com
Bryan Lavelle [Bryan.Lavelle_at_digital.com]
>My original post was :
>This is the situation :
>They have (customer company) two tape unit devices :TZ89 and TZ87.
>They want to back up to TZ89 and restore from TZ87.
>Furthermore :
>They have a Compac Tape 4 (used in the TZ89 35-70) & TK85 (used in the TZ87
20-40)
>The customer did the following :
>He used in the TZ89 a TK85 tape, and he backed up without compression, i.e.
to L device (Low Density). But this device was full at 10 G, and then the
back up failed, cause not enough space.
>Query :
>1.- Is the TK85 a 20-40 ?.
>2.- Is the Compac Tape 4 a TZ87 compliant tape ?.
In the man tz I could see all of my queries.....
But this is a response very complete :
The TK85 tape (also called CompacTape III) was used at
three native capacity points 2.6 GB in the TZ85, 6.0
GB in the TZ86 and 10 GB in the TZ87. Only the TZ87
supported compression. The capacity with compression
varies depend on the data. The 2:1 compression you see
in marketing literature assumes the most typical data,
but some data may compress better and some worse. Using
hardware compress with software compressed data will
at best not compress at all and at worst will use more
space.
The CompacTape IV (lately called DLTtape IV) is currently
used with two densities, 20 GB of the TZ88 and 35 GB with
the TZ89. These tapes can't be read at all by earlier
drives. And the TZ89 density can't be read by the TZ88.
The result you saw was the expected one; 10 GB at the
highest native density of the tape and no compression.
Thanks again...
Regards
Cristian Ramirez Villarroel
________________________________________
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> * Tel. (56 2) 6962277
7 Fax (56 2) 2471031
> * mailto:cristian.ramirez_at_sonda.cl
>
"Centenaria es la historia que escribes...ILLAPEL tierra de oro y de sol"
Received on Fri Jan 29 1999 - 12:23:35 NZDT