Re: tape parameters

In article <5se9tl$p5s@cssun.mathcs.emory.edu>, croft.evelyn@dorseylaw.com ("Croft, Evelyn") writes: :> Hello Everyone, :> :> HP has hooked up two DLT's last night. The DLT (DLT4000) is not hooked = :> up in the most efficient way, because we have no slots for a dedicated = :> SCSI channel like we had planned. We had to daisy chain the drive to an = :> existing drive to get it to work. However, my preliminary testing show = :> it takes about 60% less time to do a simple backup (HP70). Which would = :> be 60% less of a 10 hour Level-0 backup. I still need to do some = :> capacity checking, to make sure the tape parameters are set properly = :> (blocking, bpi, etc..) :> :> Any suggestions on the tape parameters? I got the impression by some of = :> the conversations out here the 10 hour archive-0 backup would be under 2 = :> hours. 60% less time would be closer to 5 hours. All suggestions are = :> appreciated. :-} :> :> (2) DLT4000 for: HP70, 9.04, informix 5.x and HP50, 9.04, informix 7.x. :> :> Eve :> Hi Eve, I've used a DLT-4000 to back up an Oracle database running under SunOS 4.1.3. In my instance the database was small enough and my backup window was large enough to take the database offline and do a level 0 dump of the filesystems using the 'dump' command. What I can tell you about the DLT-4000 itself is that: Its Linear Bit Density is 81,633 bpi and that the tape itself is 1800 feet with 128 tracks. (CompacTape IV) So the dump parameters I used were: dump 0bdsf 126 81633 230400 /filesystem /tapeunit (For 20GB) For compression I double the length, assuing 2:1 dump 0bdsf 126 81633 460800 /filesystem /tape unit (for 40GB) Maybe these values will help. - Al -- Al Dorrington awdorrin@ictest.delcoelect.com Delco Electronics - IC CIM Database & Unix Administrator Kokomo, Indiana, USA Phone: 765.451.9655