SUMMARY: 4mm tape drives

From: Dave Curado (
Date: Mon Jan 31 1994 - 21:41:32 CST

Hello all, I recently asked for opinions on 4mm tape drives.
Thanks to everyone who responded! Here is a summary of what
people said.

It seems that almost everyone is having good luck with the 4mm
drives, and that HP products are most popular. Didn't hear
any real horror stories.

Thank you! ... Dave Curado (Stephen Reilly) (SC KHOO) (Wolfgang Leideck) (Frank Dzaak)
Mike Cross <>
bern@kleopatra.Uni-Trier.DE (Jochen Bern)
"Jose Mendez Sun-VAX System Manager, Astronomy." <> (Pam Johnson)
Mark Costello <> (Marisa H. Pfalzgraf) (Rob Scott) (Andy Finkenstadt)
"Frederic Piard" <>

I assume want the device for SunOS. Digital sells, to Sun customers, a 4mm
dat tape device. It supports the standard 60 to 90m tapes with compression.
The part number is SWXTA-AA. It is fully supported.
   So, about the 4mm tape drive, what I have is about 7 4mm tape drive
I bought together with my SS10 and SparcClasic. Performance wise, I should
say is equivalent to 8mm but the tape seems to have a longer life span
when recycled ( reuse ). Hope that will help. Let me know if you received
any person comment about the drawback. bye
We use one HP 35480A 4mm tape drive and it works fine until now.
Today, after 1.5 years, the mechanics must be adjust.
It is very fast. A level 0 dump about 5Gb needs aprox 1 hours.
I have no experience with other drives but i like it.
We purchased a HP35480G DAT Drive. It supposed to dump 8Gbytes on one
tape. I modifyed the kernel (Solaris 1.1.1) and it runs fine. No
errors, no problems, It writes nearly one Gbyte per hour onto the
We have a 4mm DAT on our Vax which was worked perfectly for the last
year, its used for weekly and monthly backups and so fas has not given
us any problems. The model is TLZ06
SCSI DAT Box from Hamilton, Drive is HP 35480A, DDS and DDS-DC.
Does a great Job here, but my Colleagues one Floor higher keep having
unexplainable Difficulties using it - The Vendor claims it might be
a Damage in the Hardware. Works nicely under my homegrown Dump Script,
including Ejects. Kernel Mods (to SunOS 4.1.2) necessary.

For a 90m DAT Tape: max 8 GB, min (Compression switches off if useless)
2 GB, Average said to be 5 GB (never had a full Tape yet).

For a 60m Tape, two Thirds of the above (Surprise! ;-).
   we have sun 4c and sun 4m solaris 1.1 we are using HP3548 and HP3547 DAT DDS.
   you don't need an external driver.
   It work fine for us, at less to develop some performance modify something
   in config scsi files. New kernel.
   we had many problems with others models where you used an external drivers.

  Model DAT hp3547 uses normal density, you can storage 1.2GB 60m tape.
  Model DAT hp3548 uses compressed mode, you can storage at 8GB it
  depend, because is relative to object to compress. I obtaned near to 5GB.

  yes we are running sun 0s 4.1.3 in our sp10/41s, but the videopix
  frame grabber in sparc1+ sun os 1.1. due to problems with Sol 1.1

     Got your sun-managers query about 4mm tape drives. I have 7 tape devices
 on my network (4 DAT's & 3 QIC's) at the present time. I recommend the
 Hewlett Packard 35480A DAT drive. I has 2GB capacity on a 90 meter tape.
 I have used these drives for the past 2 years with out a failure. The price
 is about $1,200, and tape cost $12-$13 each in lots of 20 or more. Get the
 3M brand of tape (better quality) or Hewlett Packard (best quality-highest
 I do not use compression, but you can get 4GB with compression on a 90 meter
 tape. A new HP DAT drive is just out that has 4GB uncompressed and 8GB with
 compression, it has a 120 meter tape.

 I use my tapes for backups and do not feel confortable with compression.
 Another point the dat drives are upward compatable not downward, that is,
 I can read a 1.2GB tape on my 2GB drive, but cannot read a 2GB on the 1.2
 drive. Same is true of the 4GB drive, it can read a 1.2 or 2GB.

 If this is your first purchase and you do not mind compression get the 4GB
 and you can get a lot of data on one tape. The ad's say 16GB but really
 expect about 8 to 10GB.
Well, we have two systems. First is a 12-tape stacker we got from Artecon.
It sits on a machine and backs up the whole net every night; has been doing
so for about a year and a half with no trouble at all. We are really quite
pleased with it. It will run under either Sunos or Solaris.

We also bought a single DAT drive from Sun, right out of the Sun Express
catalog. We missed the fine print that says it only runs under Solaris.
Our experience so far, however, has been that it doesn't always run all
that well under Solaris either. Nothing like not being able to read your
backup tapes. There is apparently an OS patch for 2.3 that might help; I
have not yet had time to apply that.
We just purchased 2 Exabyte 8505's and they seem to work
great so far. We have 3 Exabyte 8200's and have not had
any problems with them either.
We've used Sun's 4mm in the SS1000 and they have worked well.
We use a 4mm Dallastone 8570 tape back up system. We used to have it on a
Prime and transferred it to a Sparc 10/41. It has worked well for us. We
purchased Dallastone's backup software "dtool" which automates our backups
for us each night. We have had reason to restore occasionally and have
not had any difficulties.

Actually this drive is only 5 GB, but they do sell stackers that hold
quite a bit more than that, but I'm not exactly sure how much. If you
want the company's name and phone number (I don't have an email address
for them) its:

        Dallastone, Inc.
        370 Harvey Road
        Manchester, New Hampshire 03103

        (603) 647-8168
I recently selected the new Hewlett-Packard HP1533A as the backup drive
for a large number of remotely placed Sun servers. The HP1533 is the
latest generation of DAT technology, and improves some aspects of DAT
to the point where it now easily rivals Exabyte 8mm technology. The
HP1533 uses the new DDS-2 DAT standard for tape size recognition and
higher densities using 120meter tapes. With compression disabled, the
HP1533 writes 2Gbytes on a 90 meter tape, and 4Gbytes on a 120 meter tape.
With compression, the maximum capacities (your mileage may vary) are
supposed to be something like 8Gbytes and 16Gbytes (I'm not too sure
about that last figure). The data streaming rate has been greatly
improved on the HP1533, and it now yields ~500kbytes/second.

I've had significant experience with 8mm technology, and while storage
densities are high and throughput is reasonable (for the 8500 or newer
models) I've always felt the drive mechanisms to be less than realiable.
In the past five years of using 8mm, I'd guess that an 8mm drive will
need to be refurbished on the order of 18-24 months after being put
in service. 4mm technology has always been more robust, but has lacked
storage density and throughput to match the 8mm. That gap has now been
closed, and I chose 4mm for our new Sun servers.
We have used the Gigatrend TurboDAT drives which tend to fail after ayear
of daily use, and the Archive (nee Maynard nee Connor) Python DAT drives
which haven't failed yet after 2 years.
We use a 4mm Dallastone 8570 tape back up system. We used to have it on a
Prime and transferred it to a Sparc 10/41. It has worked well for us. We
purchased Dallastone's backup software "dtool" which automates our backups
for us each night. We have had reason to restore occasionally and have
not had any difficulties.
We have two 4mm DAT drives.
One is a WangDat : <WangDat Model 2600 4mm DAT>, and the other is the one
provided by Sun : <ArchiveST 4mm DAT/DAT-DC>.

The WangDat does'nt work very well. Often the tape itself stay out of the
plastic box. The Sun one works fine, we have no problem with it.

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