SUMMARY: Quantum DLT 4000

Date: Wed Apr 16 1997 - 08:19:57 CDT

Hi Sun managers,

My original question was:
I have a question concerning a Quantum DLT 4000 tape drive unit which is
connected to a SPARCstation 10 with Solaris 2.5 installed. This tape unit
should be able to store up to 20 GBytes in native format and up to 40 GBytes

I use ufsdump to backup files with the parameters "ufsdump 0fu /dev/rmt/0hn"
followed by the file system being dumped. I have edited the /kernel/drv/st.conf
to contain the entries:

        "Quantum DLT 4000", "DLT-4000", "dlt-data";


I cannot get the unit to store more than a maximum of approximately 13 GBytes,
no matter which combination of device name I use.

First of all a big thanks to everyone who responded to my request. I received a
number of valuable tips, especially from, and

It turned out that one or more of the syntaxes in the file /kernel/drv/st.conf
were not quite correct. Quantum's Web site at which (the
Danish Sun distributor) pointed to was detailed and helpful.

The next thing to do was to increase the actual block size. Tape units of this
type are so fast that if data isn't fed fast enough, blank records are inserted
to keep the tape streaming. This problem was taken care of by overiding the
default densisty and block sizes.

I ended up using these parameters for /kernel/drv/st.conf:

"DLT4000", "Quantum DLT4000", "DLT4000";

DLT4000 = 1,0x36,0,0x8219,4,0x17,0x18,0x82,0x83,3;

Any changes made to this file are recognized during the next reboot using the
-r flag for kernel compilation.

As for the ufsdump parameters I used this example:
/usr/sbin/ufsdump 0ucbdsf 500 4100000 13000 /dev/rmt/0cbn /dev/rdsk/c0t3d0s0

We haven't yet reached the end-of-tape during dumps so now it works! However, I
would in any case recommend a backup program which can initiate a number of
parallel sessions rather than serial sessions such as "ufsdump". A program like
Legato's NetWorker (the product is called "Solstice" in Sun's implementation
for Solaris) really takes advantage of the speed of the DLT tape unit by
starting parallel sessions (typically four), thus feeding the device with a
high and constant rate of data stream.

Best regards

Paul Hostrup-Jessen
Oticon A/S
Strandvejen 58
DK-2900 Hellerup

tel.: +45 39 17 71 53
fax : +45 39 27 79 00

Internet email:

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