I have been using DLT's for many years. Before Quantum bought the
technology from DEC, they were TKxx tape drives. As for problems with
these, I have found the following:
1. Dropped from holding height, table tops, etc., they do not appear to
fail (I have never seen "tines" on the tape).
2. They do wear out, especially when aged 7 years or more.
3. They are prone to load problems, especially as the drive wears - there
is a little hook in the drive that must engage a loop in the tape. When the
hook comes loose from its catch, a service call is required to get it
repaired. I note that this happens typically less than once per year.
For reason #3 I personally would recommend against using it in an
"unattended" auto-loader.
We have been very successful using a single DLT drive with ADSM for archival
storage. Single file retrieve times are typically 2-3 minutes.
Dan
> -----Original Message-----
> From: Kelly J. Lipp [SMTP:lipp AT storsol DOT com]
> Sent: Wednesday, November 11, 1998 1:21 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Should I buy Magstar or DLT ..??
>
> I guess I would challenge the notion that DLT is industry standard.
> Quantum makes it. We can get media from a number of places, but the
> drives all come from Quantum.
>
> I'll bet IBM will be around long after Quantum.
>
> I'm the DLT bigot, too! But I'm seeing the light. If we could just have
> the best of all worlds.
>
> Kelly Lipp
> Storage Solutions Specialists, Inc.
> lipp AT storsol DOT com
> www.storsol.com
> (719) 531-5926
>
> -----Original Message-----
> From: Mark Dyer [SMTP:mark.dyer AT FLE.GMPT.GMEDS DOT COM]
> Sent: Wednesday, November 11, 1998 2:18 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Should I buy Magstar or DLT ..??
>
> Ben has some valid considerations but let's look at other considerations
> for DLT.
>
> DLT is an Industry standard, not an IBM standard.
> Because it is an Industry standard, competition is improving DLT
> capabilities.
>
> Also because of competition, media prices are continually dropping and
> there are several sources for the media.Ben Kokenge wrote:
>
> Maybe this isn't enough to help you decide one way or the other, but I
> didn't see this opinion expressed and thought it was valid.
>
> Regards,
>
> >
> > Depending on what your storage needs are will tell you what you want.
> > For me, in general, I avoid DLT tapes at all costs. They are clumsy
> > and fragile, but they do hold 35GB native. The problem with that is
> > if you want to retrieve a file off a DLT, it may be at the end of the
> > tape. With a DLT the queue-up time is much long than any of the
> magstars,
> > and the search time is even worse, so be prepared to wait several
> minutes
> > to retrieve one 3KB file. With the magstar's I wait about 1 minute to
> > get a file (and that include robot seek time).
> >
> > Another thing to consider is the life span of a heavily used tape. The
> > magstar's can be used over and over with less tape wear. A DLT needs
> > to be rotated after so many uses. Also the heads of a DLT drive wear
> > out quicker, so you will have to get them refurbished every now and
> then.
> > Oh yeah, don't ever drop a DLT from 3 feet or higher. The little tines
> > in the tape break and you are out of luck. The 3590 or 3570 form
> factors
> > are tough (trust me I know heh)
> >
> > Don't get me wrong, I think the DLT has its niche in the storage field.
> > It excels at little used; long term "cold" storage due to the price per
> > megabyte of storage. A DLT costs like $100USD/70GB (2:1 compression),
> > which is $1.4USD/GB. A 3590 costs like $65USD/30GB (3:1 compression),
> > which is $2.2USD/GB. Then you have drive costs where the 3590's are
> > like 3x more expensive than a DLT.
> >
> > One thing you might want to look at are the 3575 libraries. They are
> very
> > reasonably priced, and the 3570 tape is very slick. They restore small
> > files in less than a minute due to the fact that the tape queues-up in
> > like a few seconds, and it is 1/2 through the tape from the get go.
> >
> > One last note. ADSM is an IBM product. Magstar is and IBM product. Do
> > you think you will have any software compatability/support issues if you
> > stay with the same vendor? I have to say this about IBM, they support
> their
> > products very well. I think the 3570 will be IBM's flagship for the
> next
> > 5 year or so.
> >
> > Really it comes down to: you get what you pay for. I believe in the
> > philosophy that, "No one ever got fired for buying the best".
> >
> > These are just my thoughts,
> >
> > -ben
> >
> > Fred J Stellabotte wrote:
> > >
> > > Hi All ...
> > >
> > > We are in the final stages of purchasing ADSM ... we were planning to
> > > use DLT (StorageTek 9714), but IBM and one of their vendors is making
> it
> > > very attractive($$$) to use IBM's Magstar ...
> > >
> > > It seems that if I use the StorageTEK 9714 Library with (60 Tapes) I
> must
> > > purchase
> > > the "Extended Device Support". But If I use IBM's Magstar Library with
> the same
> > > capacity (but 240 tapes) I don't have to purchase the Extended Device
> support
> > > ...
> > >
> > > With the quotes I am working with the Magstar Unit is more expensive
> but the
> > > total
> > > quote comes out less because of the Extended device support.
> > >
> > > Are there any real benefits to using Magstar ..???
> > >
> > > What is the average cost of the Magstar Tape vs the DLT tape ..???
> > >
> > > Is having a smaller tape a plus with ADSM ...?
> > >
> > > Is Magstart really faster in recovery as the Vendor Claims ..???
> > >
> > > Will IBM Abandon the technology ..???
> > >
> > > Thanks so much .....
> > >
> > > -Fred
> > >
> > > ____________________________________________________________
> > > >| == Fred J. Stellabotte
> > > stellabotte AT hazeltine DOT com
> > > >| == Manager Technical Support
> > > >| == _______________________________________________________
> > > >| == GEC - Marconi Hazeltine Voice:
> > > (516)262-8308
> > > >| == 450 Pulaski Road
> Fax:
> > > (516)262-8290
> > > >| == Greenlawn, New York 11740 Beeper:
> (516)453-4228
> > > _____________________________________________________________
>
> --
> Mark Dyer
> Systems Administrator e-mail: mark.dyer AT fle.gmpt.gmeds DOT
> com
> Service Delivery - UNIX Team voice: (810) 236-0373 [8-446]
> fax: (810) 236-9290 [8-446]
>
> EDS North/West Region
> Mail Stop 485-184-110
> 902 E. Hamilton Ave
> Flint, MI 48550
|
