SUMMARY: DLT4000 tape operation ...

From: Richard Roberto (
Date: Wed Mar 03 1999 - 23:22:34 CST


My oroginal question was probably badly stated since so many people
misunderstood it, but I was trying to find out how to eject the tape
froma DLT4000 (unipack -- not autoloader). Tha answer is that you
can't. The ioctls for "offline" are intercepted by the autoloader
versions of the drive and suitable autoloader commands called.
Since I have not autoloader, this doesn't happen and there's no way
to eject the tape programatically.

The other question was similarly misunderstood, but I got some good
feedback anyway. I am using default blocking factor (126) to do
ufsdumps to the drive but the performance pales in comparison with
its advertised specs, so I was wondering how to improve it. The
quantum site mentions increasing the "record size" and says it can
handle as large as 16MB records. 15 minutes after this drive
arrived it was put into production so I never got a chance to fiddle
about with blocking factors to see if throwing more data at it at a
time would improve things, si I figured I'd ask here. Since nobody
seems to know, I may spend a saturday here mucking around timing
things since I'd like to shrink the window needed to get this done
as much as possible. "Just use 126" was the overwhelmingly most
popular suggestion on this, which is exactly what I'm doing now.
I'd just rather get my money's worth out of the drive if possible.

Thanks to:

Dale Shaw <>
Charlie Mengler <>
Ronald Loftin <>
Jay Lessert <>
Arthur Darren Dunham <>

Sorry if I missed someone.



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:13:16 CDT