Seagate STD6401Lw

[jellyman5264]

Hi
I was able to get a used external Seagate 4mm tape drive (STD6401LW)
and I would appreciate some help with the configuration. I purchase
a used AHA 2940UW to work with the drive. The tape does back up, bu
very slow and many soft write errors. Can one of you please tell m
the correct settings that I should use on the 2940UW and any othe
info that will make the drive work better? The last backup that wa
attempted indicated that it would take over 5 hours to back up 13 G
? The drive makes many “clicking” sounds when backing up (perhap
the head seeking ???) I have used a cleaning cartridge on the driv
and using new 4mm media

Thanks for your help
Bil

 

[Paul]

I was able to get a used external Seagate 4mm tape drive ( STD6401LW )
and I would appreciate some help with the configuration.  I purchased
a used AHA 2940UW to work with the drive. The tape does back up, but
very slow and many soft write errors. Can one of you please tell me
the correct settings that I should use on the 2940UW and any other
info that will make the drive work better?  The last backup that was
attempted indicated that it would take over 5 hours to back up 13 Gb
?  The drive makes many ³clicking² sounds when backing up (perhaps
the head seeking ???)  I have used a cleaning cartridge on the drive
and using new 4mm media

Thanks for your help
Bill

http://www.digiconcepts.com/seagate_tapebackups_12.htm

"including a diagnostic utility to confirm proper installation."

"And routine maintenance is virtually eliminated due to the
drive's innovative head-cleaning mechanism."

"165 MBytes/min native transfer rate,
up to 330 MBytes/min compressed;"

Get out the diagnostic utility and test it.

Tape drives can operate in two modes. "Start/Stop" or "Streaming".
The clicking could be "Start/Stop". (I don't keep up on tape
technology, and maybe the operation you are seeing, is normal
for a device of this type.)

Backing up many small files, using a program that moves the hard
drive heads all over the place, may result in an insufficient queue
of work to keep the tape drive streaming. Find a very large file,
like 1GB in size, and attempt to back up that one file. That will
eliminate head seek on the hard drive as the source of the problem.
Disable compression, so the software and processor performance
is taken out of the loop. Then see if the clicking stops while
the 1GB file is written out.

At 165MB per minute true write rate, the SCSI bus only has to
carry 3MB/sec. Even async SCSI could handle that. My guess would
be, if it is working at all, then the SCSI part is OK. I'd
be real curious what the diagnostic will tell you.

Does the tape drive throw errors while it is reading or
writing ? Does the backup application have a place to monitor
the sense errors coming back from the drive ? Any errors
coming back would also hint at any problems it might be having.

In watching people use tape drives at my work, I see the
greatest weakness, is the level of maintenance they receive.
In some cases, I've seen people religiously doing backups,
only to discover later that all the tapes are blank, because
the drive was filthy. Imagine if you buy a used tape drive
from a clod like that. Cleaning is only really effective,
if the thing is kept clean in the first place - one application
of a cleaning cartridge won't do anything for you, if a drive
has been abused.

So find that diagnostic utility...

Paul

 

[jellyman5264]

Thank you very much for your reccommendations Paul. I did not receiv
any S/W with the unit. I shall try to find the Diag S/W. Through
great deal of hunting around I was able to find the correct setting
for the card / drive at the Quantum site. The drive seems to perfor
better with large files (much less seeking) Once concern that I hav
now is termination. The Quantum documentation states that the driv
requires a LVD terminator. The unit came with a terminator tha
simply has "ACTIVE" written on it. I do have othe
terminators lying around on some old SCSI drives both of which stat
"LVD/SE". Should I try one of those instead? You had mad
reference to cleaning, I do have a couple of cleaning tapes on hand.
How many times should I run the cleaning tape through? I have no ide
the last time the unit was cleaned. I also have a tape hea
demagnetizer, should I try that as well
Best regard
Bil

 

[Paul]

Thank you very much for your reccommendations Paul.  I did not receive
any S/W with the unit. I shall try to find the Diag S/W.  Through a
great deal of hunting around I was able to find the correct settings
for the card / drive at the Quantum site.  The drive seems to perform
better with large files (much less seeking) Once concern that I have
now is termination. The Quantum documentation states that the drive
requires a LVD terminator. The unit came with a terminator that
simply has "ACTIVE" written on it.  I do have other
terminators lying around on some old SCSI drives both of which state
"LVD/SE". Should I try one of those instead?  You had made
reference to cleaning, I do have a couple of cleaning tapes on hand.
How many times should I run the cleaning tape through?  I have no idea
the last time the unit was cleaned.  I also have a tape head
demagnetizer, should I try that as well?
Best regards
Bill

AFAIK, "Active" means SE or single ended. LVD is low voltage
differential, and a lot of current generation devices will be
LVD/SE, meaning they are backward compatible with either method.
If an SE component shows up on the bus, then they all use SE.

If you use the Active terminator, the bus speed would be limited
to SE speeds. All the entries in the table here, that allow 12
meter cable length, would be LVD. SE would be 40MB/sec or less.
But your application only needs an average of 3MB/sec, so SE
operation should be just fine.

http://en.wikipedia.org/wiki/LVD_SCSI

http://www.econ.ucsb.edu/~mikeo/jay/scsifaq2.html

Your controller card also has a say in this. The
AHA 2940UW would likely be SE only. The 2940U2W has
an Ultra2 bus segment and an Ultra bus segment.

http://graphics.adaptec.com/pdfs/installation_guides/aha2940u2w_ig.pdf
http://graphics.adaptec.com/pdfs/installation_guides/aha2940uw_ig.pdf

I would definitely keep the tape head demagnetizer away from the
thing. You can do more harm than good.

According to this, DDS-4 is helical scan, similar to a VCR.

http://en.wikipedia.org/wiki/Digital_Data_Storage

"A DDS tape drive uses helical scanning for recording, the same
process used by a video cassette recorder (VCR). There are two
read heads and two write heads. The read heads verify the data
that has been written (recorded). If errors are present, the
write heads rewrite the data."

There are software downloads here - maybe TapeRx is the diagnostic?
http://www.quantum.com/ServiceandSupport/SoftwareandDocumentationDownloads/DAT40Drives/Index.aspx

The drive mechanism was likely made by Certance, then Certance
was bought by Quantum. The only thing I cannot figure out, is
how Seagate got in on this.

http://uk.insight.com/apps/productpresentation/index.php?product_id=SGGA03UXQ

For the cleaning tape, I would only use the product specified
by the company making the drive. The cleaning tape will be good
for removing loose material, but if there really was a problem
with the heads, I doubt the cleaning tape would fix it. At least,
when I attempted to "clean the shit" out of a busted tape drive
once, I got nowhere.

Paul

 

[jellyman5264]

One again, Many thanks for all the info Pau

I shall try to get the drive going agai

Best regard

Bil