HP OpenVMS Systems

Enabling Tape (DLT) Data Compression?

» close window

The Question is:

 
Is there a way in VMS 6.2 to turn on the compression density on a DLT drive
like a TZ87.
 
In the BACKUP command there is a /density=n switch but the vms help just
talks about the setting fir magnetic tape in bits per inch, which sounds
like a reference to 9 track tapes and not DLT's.
 
 

The Answer is :

 
  Use /MEDIA_FORMAT=COMPACTION
 
  To determine the current (SCSI tape) device compression status:
 
    $ Devpend2 = F$GETDVI("$n$MKcxxx:","DEVDEPEND2")
    $ Comp_sup = %X00200000
    $ Comp_ena = %X00400000
    $ IF (Devdpend2 .AND. Comp_sup).EQ.Comp_sup
    $ THEN
    $   WRITE SYS$OUTPUT "Compression is supported"
    $ ENDIF
    $ IF (Devdpend2 .AND. Comp_ena).EQ.Comp_sup
    $ THEN
    $   WRITE SYS$OUTPUT "Compression is enabled"
    $ ENDIF
 
 

  

     

     
answer written or last revised on ( 10-DEC-1999 )
     
» close window