On Thursday 30 September 2010 15:40, Ron Guerin wrote:
> Matthias Johnson wrote:
> > I know several people must be involved in backups so I thought I might
> > pose this question.  What backup media do you / would you use for a
> > business?  I know there has been some that have stopped using tape
> > media and now do backups to disk but is this a smart approach.  To
> > quote the O'Reilly book PC Hardware in a Nutshell by Robert Bruce
> > Thompson and Barbara Fritchman Thompson.
>
> I can only speak for myself, but away from books, out in the real world,
> tape and the people responsible for using them are the #1 cause of
> backup failure.  If disks were really as bad as they're trying to
> suggest, nobody use them for _primary storage_, but we all do, don't we?

Interesting thing about this: a friend recently called me up and decided to 
create a "mirror" of a machine in order to back up the original as well as to 
set up a fail-over in case the first one goes down.  He decided to try using 
an SSD device in place of a hard disk, thinking that the SSD is "more 
reliable".

I wasn't sure what to say.  Are SSD disks more reliable than spinning hard 
disks?  What is the *actual* reliability on hard disks -- which 
experimentally have been shown to fail more often than manufacturer MTBF 
numbers.  Since SSD disks are so new, is it known how often those fail?

Not easy to answer all that.  I simply told him to to go with the SSD so that 
he could test whether the SSD in the 2nd box was more reliable than the hard 
disk in the 1st one.

> I started switching clients to disk backups about 5 years ago.  They
> have gone from highly unreliable backup systems based on tapes that
> often verified but could not actually be read when needed, and people
> that weren't changing their tapes, to a backup system that has been
> there for them 100% of the time they need to recover something.

I don't like tapes, either.  Too many reasons why to list them all.  Better 
simply to save the tirade since I'm already mostly speaking to the choir.

> Please note however, that people are still the main point of failure.
> Unless you automate offsite backup as well, you're still going to be
> relying on people to rotate external drives on a schedule that meets the
> needs of the situation at hand.  During my financial industry days, you
> could rely on people to handle backups correctly because it was often
> their only job to do.  In my small business days however, the task of
> rotating drives seems only to get done if the owner/CEO/CFO or some
> other top rung executive personally does it themselves, and getting to
> the point where they'll do that usually requires discovering that even
> threats to fire people will not get them to perform their backup duties
> competently.

Doing backups is often an an "invisible" job which isn't caught when it 
doesn't happen.  Nag emails warning when it doesn't get ignored.  People 
sometimes have to leave early thus don't bring a backup off-site.  Mistakes 
can happen in tape rotation so the full monthly tape backup gets overwritten 
with an incremental.  Etc.  Lots and lots of ways it can go wrong.

-- Chris

Chris Knadle
[email protected]
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