Re: Cheapest way to acheive RAID5 ?

[David Greaves <david@xxxxxxxxxxxx>]

Dean Barrett wrote:

> As im now a fully fledged Cinemar convert i'm starting to grow my hard
> drive
> based DVD collection. Reading about reliable solutions i've noticed
RAID5
> mentioned a few times as the safest way to keep your collection.
>
> Had a quick Google and look round EBay, and see a selection of
controllers
> from £30 up - on overclockers there are a couple of RAID 0,1,5,10 JBOD
> cards
> at £70.00 which look good - in both SATA and Standard, as i have a
> standard
> 250gig i guess i should stick with the standard one.
>
> Has one got any advice on this type of thing ? - i assume i shall have
to
> scrap my Shuttle to get 5 drives in a box, i also assume i'll need a
> bigger
> PSU etc.
>
> Suggestions appreciated, and is RAID5 the best way to protect them ?
>
Are you on windows or linux?
I can help out a lot with any linux issues (I run a 1.2Tb sata based
raid5 with a pata hot standby for my MythTV store)
One thing to watch with raid5 is that it can range from trivial to very
very tricky to 'just add another drive later'.
There are several strategies for dealing with this.

Also worth considering what happens if your cheap raid5 controller dies
for some reason and they're no longer available in 2 years time.
Less likely with companies like 3Ware.
Also note that many cheap raid controllers aren't 'real' raid
controllers. They're often just multi-channel cards with drivers that
plug into the OS. Some, like certain Promise cards have hardware
'assistance' for the raid calculations - proper controllers do it all on
the card. This isn't usually a big deal for (relatively) low performance
home systems.

Finally, heat and poor PSUs are major causes of failure for homebrew
raid systems.
You're wasting your time cramming 5 or 6 drives into a tiny case with no
heating - you'll end up with a _less_ reliable system.
It doesn't have to cost the earth - I bought a cheap full tower case and
cut a hole in the top for a 120mm fan, I put another 120mm fan inside
the case too and upgraded the PSU.

HTH

David