[asterisk-users] Re: While the VoIP-Info.org site is down...

[Dave Cotton]

On Thu, 2007-03-15 at 10:15 +0100, Benny Amorsen wrote:

> Not as slim as manufacturers want to make you believe. RAID drives
> tend to be purchased at the same time, so they are often from the same
> batch. They are then subjected to exactly the same load in exactly the
> same environment. Is it any surprise that they fail at the same time?
> 
> Especially if they are kept running for a very long time and then shut
> down by a power failure.

It all comes back to perceived security. As you rightly say the disks in
a RAID will have a good chance of failing at the same time because not
only being out of the same batch but probably constructed one after the
other. This normally will not be a problem for the manufacturer because
they would be installed in different machines with different usage
rates. If you really want to avoid this the discs would have to be
selected out of different batches. It should never be forgotten that
originally RAID stood for Redundant Array of Inexpensive Disks, I never
could understand how a RAID could be made up using SCSI disks seeing
that they are certainly not inexpensive.  

The other common misconception is tape backups there is an old story in
computing that the main problem with tapes was that the bits fell off,
how many people actually test the restore capability before they
actually need it?

-- 
Dave Cotton <dcotton at linuxautrement.com>