> On Fri, 1 Mar 2002, michael brown wrote:
>
> > > Yikes, more to think about...
> > >
> > > I am looking at Firewire hard disk units made specifically for
back-up.
> > Does
> > > anyone have experience with these?
> >
> > They are very fast.  Basically capable of same speed as an internal
drive.
> > 400Mbps is pretty fast.
>
> Yeah, but that's Firewire's transfer speed ... not necessarily the
> drive's.  If a drive can't keep up, you might burst 400kb/s, but your
> overall won't be that fast.

That's why I said that the fire-wire drive would be basically as fast as an
internal drive.  ;-)  The comment about 400Mbps was just a side note.

> > I have a personal thing against tapes.  I do not ever trust them to
work.
> > The problem with tape is you can't tell if the tape has been damaged by
a
> > magnetic field by looking at it, you also can't tell if you are going to
be
> > able to read it, until you try, UNSUCCESSFULLY  :-(  The big thing is
that
>
> Read verification should be done with hard drives, too, if your data is
> _actually_ important.  I'll bet I've put data onto a hard drive and not
> been able to read it back as many times as tape has failed me.

The drive does a pretty fair job of self error correcting the data that it
can read.  Usually when a drive just can't read a sector and retries over
and over, it's most likely the media literally detaching from the platter.
When an IDE drive suddenly develops some bad sectors, it's life is over
right then.  It's time to take your data and run, cuz the problem is NOT
going to get any better.  It WILL (absolutely guaranteed) develop more bad
sectors.  This is what most drives do, long before the "click of death" sets
in.  IDE drives that have detectable bad sectors should never be used.
Unfortunately, many people don't know or believe this.

> > doesn't guarantee you will be able to read it again.  In fact, you have
just
> > decreased the odds that you will be able to read it again.  Believe me,
> > murphy's law was invented due to tapes.  With hard drives, you usually
have
> > more warning before a total failure occurs.  Don't trust tape, it works,
but
>
> I'd say that's subjectto the nature of the failure ... how often does a
> drive just up and die compared to magnetic data related failures?

Most (not all) of the failures I have personally seen (and that's been a
bunch) started out subtly.  Most have been related to gradual media failure.
I have seen a few (very few) drives that died after being run continuously
for several years and then turned off overnight.  That seemed to be a
bearing/lubrication related failure.  I have never (never, ever) seen a pc
hard drive self destruct internally suddenly and without any warning
whatsoever.  I have seen allot of people using drives that should have been
replaced long before.  :-(  I hate to see people lose data, but I have seen
so many occasions of people not taking it seriously until it's too late.
Any extra copy of your data (on disk, tape, punched cards or paper-tape if
that's all that's available) that you can have is to your advantage, and
preferably that copy is somewhere else.

Your best backup, IMHO is another copy on another drive.

> Just my $0.02.
> -- Mitch

My (long winded again) two cents several times over.  ;-)

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