SUMMARY: 5G Exabyte drives with non-Exabyte tapes

SUMMARY: 5G Exabyte drives with non-Exabyte tapes

Post by Ian Farquh » Fri, 04 Sep 1992 15:19:04

Recently, I posted the following query:

Quote:>We've recently taken delivery of a 5G Exabyte tape, and I was hoping for
>some battle stories from anyone else who had used them, particularly
>with non-Exatapes.
>We've been using the old 2.3G drives for some time, and have had no major
>problems using the standard Sony 8mm tapes (which cost us in the region of
>$12, compared to about $40 for an Exatape.)  However with the 5G drives I
>am somewhat wary of the Sony tapes.  Has anyone got any opinions or had
>any experience using non-Exatapes in the 5G drives?
>Thanks.  Email me, and I will post a summary to the net.

I received replies from the following people:

The greatest of thanks go to everyone who answered.  The general consensus
on the subject of using Video tapes was:

        Yes, they're okay               4
        Yes, but a qualified answer     3
        No                              3

I also, after I posted this, spoke to an engineer from Exabyte Australia.
He said that Exabytes do perform a verification test during their normal
operation.  First they do a write, then a read at 35% of the write amplitude.
If there is a verification error, the unit waits for 11 tracks (each track
store 8K), and then tries again.  This at least provides some data integrity.

He also said that Exatapes are manufactured by Sony, and that the Exatapes
are guaranteed to be the best 10% of the production run.  All Video 8
tapes manufactured are now of the metal-oxide variety, meaning that they
are suitable for Exabytes, although he commented that whatever we would be
using would be in that bottom 90% of the quality range.

Here are the other answers I got:


Quote:>I have been using an EXB8500 daily since 3 July 91 with Sony P6-120MP
>tapes (I pay about US$6 for them) and have had no problems.


Quote:>well, the tapes don't care if 2.3GB or 5GB is written to them. We have
>good and bad experiences with all tapes (although the original Exabyte
>tapes never showed problems). We only use 8mm tapes that are rated for
>data storage, i.e. no tapes meant for Video-8, but I'm not sure if there
>is a difference at all. The last batch we bought (Sony QG-112MA) has been
>quite flakey (i.e. an extremely large number of retries by the streamer).

>BTW, the standard tapes will only hold 4.3GB.. for 5GB you need slightly
>longer tapes.


Quote:>I seems the one needs to clean the tape drive more often when you use
>non-exabyte tapes.  I also have a vendor the we have bought 5GB tape drives
>from who says that they will void the warranty on the drive if non exabyte
>tapes are used.


Quote:>We are using normal Sony-Tapes in 5 Gigabyte 8500-Exabyte-Tape Drive
>and until now (1/2 Year) we have had no Problems with this Tapes.

>Kirsten Beiss


Quote:>We've been using regular Sony P6-120MP tapes (about $6 US each) in our
>8500 for about a year, no problems.

>We always do a "test write" of each new tape just to make sure it functions,
>and have found two tapes total (out of a 400-500 tapes) that simply would
>not work.  I don't know how this compares to "data grade" tapes.

>Some folks compromise and use "consumer" tapes for their daily backups, which
>presumably contain lots of redundant data but constitute most of your tape
>usage, and "data grade" tapes for archival storage.


Quote:>We have several of the 5GB (8500) drives.  We found, very quickly, that
>the video grade 8mm tapes gave large numbers of errors, even on write;
>most of the errors were apparantly "soft" and thus recoverable,
>but resulted in *huge* slow-downs in actual throughput.

>We are now exclusively using Sony "data-grade" tapes (the 112m cartridge
>has part number QG-112).  We are buying them from a local distributor for
>less than $12 each, quantity 50.  (We had been paying $6/each for
>the video grade tapes.)  It's well worth it.   The tape media related
>error rates are now essentially zero.

>(We're doing all this on a pair of Epoch file servers, with 8500s in
>10i robotic units.)

>On the other hand, I have no idea of prices in your area :-).


Quote:>We have been using sony tapes in our Exabyte 5GB 8mm tape drive for
>several months with no problem.  The tapes we use are the data quality
>NOT the video tapes.  The video tapes have many many problems.


Quote:>We are using Sony video-grade 8mm carts. with our Exabyte 8500
>(and formerly with an 8200).  No problems have been encountered.
>I hear that the new production runs of these carts. leave the tape
>positioned a bit past BOT, and so the Exabyte kicks the cart out
>the first time it's loaded.  Push it in a second time, and the cart
>works fine from then on.


Quote:>We have used Sony Metal MP120 in 5G dirves for a long time and don't
>see any problems unless you write on the tape too many times.


Quote:>We have hundreds of them.  We prefer the Fuji tapes to the Sony tapes,
>but have not had any particular problems with either (using
>thousands of tapes).  We dont think the datagrade tapes are worth
>the money.


Quote:>Well, this is just personal opinion.

>Video tapes cost us around $6-8 (US), while exabyte tapes are around

>I look at it this way. You are cramming twice the data on the tape.
>Why skimp? Compare the tape prices for backing up the same data on
>a 5G exabyte tape to the eqivelent # of 1/4" tapes or 1/2" tapes.
>Exabytes are much cheaper.

>How'd you feel if you saved a few hundred dollars on the cheaper tapes,
>and then had a restore problem?

>I watch for deals on other stuff and skimp where I can. I don't really
>want to skimp on backups. My *is on the line....


Ian Farquhar                      Phone : + 61 2 805-9400
Office of Computing Services      Fax   : + 61 2 805-7433
Macquarie University  NSW  2109   Also  : + 61 2 805-7420


1. SUMMARY: 5G Exabyte drives w/ non-Exabyte tapes

We have been using the Video8 tapes in our Exabyte 8500 with no
apparent problem until recently.  After about 12 backups on a
particular tape, we start getting a lot of write errors, and the
backup fails.  The problem is remedied by using a new tape.  Is
this a normal life expectancy for the video tapes?  Can I
expect a longer lifespan for the data grade tapes?

A related concern is how often to clean the drive.  Currently, I
use the "official" Exabyte cleaning cartridges, and clean the drive  
once a month.  We are backing up about 20 GB each month.  Do we need
to clean the drive more often, since we are using the video tapes?

Thanks for your help.  Please respond by email to the address below.
Bob Ford                           (814) 234-8592x36

Philadelphia Phillies

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