[rescue] Re: Quick EXB-210 questions

[Robert Novak]

On Mon, 27 Aug 2001, Greg A. Woods wrote:

> > > (Who the heck would want that junky AIT crap anyway?  It's engineered as
> > > if a M$ designer was in control -- ultra-stupid!  STAY AWAY!)
> > 
> > How so?  I've dealt with them a couple times and had no problems.
> > What parts do you find stupid?
> 
> well, just compare the drive and the media side-by-side with an
> equivalent capacity Exabyte Mammoth drive and media.  They both do the
> same thing in more or less the same with, at about the same speed, with
> about the same features, on much the same grade of metal particle tape.
> Also compare the designed-for duty cycles of the drives and the average
> (not burst!) transfer speeds.

MP, AME, and AIT physical media are different. According to several
sources the tape life (years and passes) are about the same. In real life
settings, I got about 4MB/sec/drive on Mammoth and 10MB/sec/drive on
AIT-2, each with two drives on the same bus, and with a 50/50 mix of local
and network storage going to the drive. This was based on 2 years with the
Mammoth and 1 year with the AIT-2 changers/drives. 

> Now which one do think was designed for production backups?

Slide film, obviously. You have TOMA syndrome here, but that's okay.

> Heck you even need special software to take full advantage of all the
> extra-cost (per drive *and* per tape!) of the AIT.  

This is not accurate from any real world setting I'm aware of, unless
there is some element of "full advantage" which specifically specifies
"works with such-and-such software." I used Legato Networker and Solaris
ufsdump and they both made quite substantial use of the AIT2 drive and
media. Same with Mammoth 1. 

I am not aware of any magic in the AIT world--it just works. I got a
consistent 125-130GB/tape (50GB native) using the hardware compression as
/dev/rmt/#hbn with no driver hacks or special software. This was only
observed over the course of 11 months, with about 300GB of data 50/50
local and network, so it may have been an anomaly. Your mileage may vary.

What I really wonder though, is if you're saying AIT costs more by volume
(i.e. $/GB) than Mammoth or DLT? If so, back it up with some real prices
and real world compression rates, not list price and published rates.

> Exabyte's SCSI mode pages aren't exactly 100% standard either, but at
> least they're fully and publicly documented and can be used without
> major driver hacks.  If you want a machine readable label for your
> robot Exabyte supports a standard SCSI bar-code reader in their
> changers -- heck even Amanda supports that!

Well, this one doesn't make a lot of sense. I've used Qualstar and Exabyte
Mammoth libraries, and Overland Data and (soon) ADIC AIT2 libraries, and
they ALL offer barcode readers which are supported under conventional
software packages. Exabyte even has AIT these days, by the way, alongside 
DLT and M2.

I don't see the existence of a standard barcode reader as a good reason to
choose one medium over another. Kinda like choosing one car over another
because you can get fuzzy dice for one of them. 

> Now of course I wouldn't buy either one because of the helical-scan
> nonsense, 

Progress is hard. Take it slowly. I haven't had to manually splice a data
tape in, well, ever... so there's not much advantage to linear scan.

Dang, I got trolled again. I said I wasn't going to get back into this
argument. 

Robert Novak, Indyramp Consulting * rnovak at indyramp.com * indyramp.com/~rnovak
        "And it's been a long December and there's reason to believe
           Maybe this year will be better than the last...." -- counting crows