His main points are correct:

* RAID increases the complexity of the system
* Many people don't understand the handicaps RAID introduces, and only
focus on the benefits.
* While there are exceptions most consumer RAID setups produce more
complexity and associated lower reliability than is returned in
benefits. (though some of his cost/benefit ratios are based on
subjective measures)
* RAID 0 (striping for speed) is only benefitial when 1) HD throughput
is the bottleneck and 2) Access time is not an issue (ie, seeking
doesn't speed up, but throughput does)
* RAID 1 (Mirroring) is no replacement for a good backup
* RAID 5 and 10 are really not interesting as they either have the
same problems, or are simply not applicable to the customers.

Regarding specific bits of it:
His estimate of 20-30% of RAID tech support issues is in no way
comparable to the hard drive failure rate.  All he's really saying is,
"RAID requires more configuration than a hard drive, and we have to
support it more than hard drives"

It's not a complete article - it really should go through the benefits
in addition to the problems RAID introduces.  He doesn't point out,
for instance, that while RAID 1 isn't a replacement for backup, it
does keep the system up and running in the face of failure, which no
other backup system will do - only redundant systems/disks (ie, RAID)
will do that.

He suggests that it's a hassle to re-sync a RAID 1 drive, but the
reality is that it depends on the failure and what you plan on doing
about it.  It's certainly more of a hassle to rebuild your system from
scratch with a backup and a new hard drive, especially if it's just
the RAID card that failed - buy a new one and install it (you'd have
to buy a new HD in the other scenario anyway).

He also gives interesting statistics about hard drive failures and
RAID support issues, but he never mentions RAID card failures, and HD
failures in RAID arrays.  Sounds like either they don't track it (ie,
it's not frequent enough to track) or the numbers weren't conducive to
his argument.

Still, his points are valid - most people, even those that think they
need one, don't need a RAID array.

But I'll tell you what, my system was never faster than when I had two
10k Raptors striped for my main windows drive.

Hard drives are still significantly slower than the CPU and main
memory, and even in systems with 4GB of ram a significant amount of
paging occurs.

-Adam

On 2/24/08, Apptech <apptech@paradise.net.nz> wrote:
> He argues that RAID typically reduces reliability.
> ie done well it can be an improvement, but ... .
>
> Makes some sense.
> What do others think
>
>    http://www.pugetsystems.com/articles?&id=29
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