Subject: Re: Reading DLT does not stream?
To: Jukka Marin <>
From: Felix Deichmann <>
List: netbsd-users
Date: 09/02/2004 17:47:10
Jukka Marin wrote:

>> try playing with the blocksize IE:
> No change, it keeps rewinding no matter what the bs is.

OK, another approach:

Is it possible that the streamer's cache is NOT enabled?

An excerpt from the DLT FAQ


I've recently connect a DLT to my system.  It's unbelievably slow.
What gives ?


It's common for a host to disable the drive's internal cache
if it doesn't recognize the product name string.  If this is
true, the DLT's performance can be reduced to the sub 100KB/sec

A second possibility is the record size being used by the host.
The DLT 2000 is especially sensitive to record size.  In general,
the bigger, the better.  We recommend 32K, or even 64KB records
if possible (up to 16MB records are supported).  In general,
any record size greater than 8KB should result in a
bottleneck-free tape drive.  Any record size less than 8KB will
give performance problems.  Many software packages default to
512 byte records.  This will result in throughput in the
100-200 KB/sec range.

On a SGI for example, every drive needs an entry somewhere to work 


I think it's time now for a NetBSD SCSI expert to join the discussion :-)
Is NetBSD similar to SGI in this respect? Or does the "DLT VS80" need a 

Jukka, have you double-checked that the disk is fast enough concerning