Re: newbie asking about autoloaders - toasters

4 Mar 1999


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From bmw@visgen.com Wed Mar  3 19:26:09 1999
From: Bruce Walker bmw@visgen.com
Subject: Re: newbie asking about autoloaders
To: kfischer@rsinc.com (Kathy Fischer)
Date: Wed, 3 Mar 1999 20:20:43 -0500 (EST)
Cc: toasters@mathworks.com
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Kathy Fischer writes:
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Can anyone out there recommend an autoloader (DLT type), or warn against any
for use with the toaster?
If it doesn't have to be DLT, the Exabyte Mammoth tapes get excellent
performance and are cheaper.  I am getting better than 5 Mbytes/sec
continuous xfer, which lets me backup 65 Gigs in about 4 hours
using dump on the filer.  This is to an Exabyte F220 autoloader
(10 tapes) running in dumb mode, attached directly to an F720.
Well almost directly; I have a Rancho differential SCSI to single-ended
converter mashed in between the Exabyte and the F720.  I ordered
both the F720 and the Exabyte at the same time and failed to notice
that the 720's come with differential SCSI!  I sure croaked that
filer bad when I connected a plain 68pin to 50pin HD SCSI kluge
adapter to it.  Kernel fault and core dump.
Supposedly, BudTool works with the Exabyte too, but I may never be
able to find that out :-)
On the performance thing: it's important that the filer be able to
get the data rate up high enough to prevent the DLT tapes from
shoe-shining which brings down their effective xfer rate a lot.
I had a DLT4000 drive for a while before I bought the F220 and it
shoe-shined a lot when driven from an F330 filer.  It only managed
to do about as well as the 4mm DAT drive it was temporarily replacing.
I kinda like helical scan technology for that start/stop ability.
Cheers!
-bmw   | Double helix in the sky tonight
       | Throw out the hardware
       | Let's do it right   -- Steely Dan; Aja
Hi,
BudTool supports most all libraries that are manufactured.  This includes the Exabyte 220.
There are a number of DLT libraries with DLT7000 and DLT4000 tape drives in them.
In my opinion, DLT is the defacto standard in the industry.  Mammoth may be a little
cheaper, but was never really accepted widely by the market.
The top three Tape Library manufacturers are StorageTek, ATL, and Breece Hill.  Any tape library 
from these manufacturers will give you very good service for the long term.  If you go with
8mm technology such as the Mammoth or Sony AIT, then Exabyte or Spectrologics makes excellent
tape libraries to fill this nitch.
As an aside, the top three Tape Library manufacturers I mentioned above (STK, ATK and BH) decided to
only support DLT tape technology for OpenSystems (UNIX) and passed on Mammoth and AIT.
Randy Butler
System Engineering Supervisor - Western Region
PDC Solutions, Inc.			phone:   972-446-2644 x15
Systems Engineering Solutions		  FAX:   972-245-9320
1445 MacArthur Drive, Bldg. 1, Suite 116
Carrollton, TX  75007
E-mail: rbutler@pdc.com
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