[mythtv-users] Should I use LVM on this new raid?

Jay R. Ashworth jra at baylink.com
Mon Sep 24 12:53:59 UTC 2007

On Sun, Sep 23, 2007 at 10:10:01PM -0500, Brian Foddy wrote:
[ quoting me: ]
> > Evaluate carefully the relative cost of drives, as well, 5x500GB RAID5
> > may give you the same amount of storage for less money then 2x1TB
> > RAID0; the largest capacity *anything* is always more than twice the
> > price of the next one down half its size.
> >
> > 500GB Seagate 7200.10s are about a bill right now.
> Yes I know the risks of RAID0, I've lived with a 5x RAID0 for
> probably 4-5 years now.  As the budget allows, I'll add 
> a couple more drives and migrate it to raid5.
> I was originally thinking the 500GB drives would be the way to
> go, primarily because of the very attractive price/size ratio.  That's
> even why I paid extra for a 8 port raid card cuz I thought I'd 
> be in the 5-8 drive range.  But when I started looking around 
> at other options there were a few factors that shifted my decision.
> 1.  I discovered the new Seagate 1000GB drives are not just bigger,
> they are much better.  32MB cache vs 16, and the internal throughput
> is roughly 40% faster (~105 vs 70 (can't remember the units)).  And
> they use less power / run cooler. They are a whole new generation 
> drive vs even the 500/750GB perpendicular  drives that are so cheap 
> right now.

I hadn't actually looked at the 1TBs (I didn't actually realize Seagate
had gotten one out the door, honestly), so I didn't realize the price/
performance ratio jump was that steep.  Yes, that sounds like a good
judgement call...

> 2.  Since I wasn't buying all the drives right up front, I tried to guess
> what would be the drives I'd wish I had in 6-12 months, and what would
> be the sweet price/size ratio at the time, knowing once you pick a 
> disk size in a raid, its very hard to change it unless you start a new
> unit or replace all the old drives.  This clearly pointed to the 1000GB
> drives.
> 3.  The final price on the new drives, was actually not that far out
> of reach.  New Egg has the ES.2 series 1000GB drives for $370 ea.
> Within reason of the price/size of an older series 500 ES.1 drive.

Twice as much storage for 3.7 times the cost... I dunno; that's still
pretty close to the edge.  Sure, they'll get cheaper before you buy the
other three... but how much?

> These factors lead me to going with just 2 1000GB drives with
> number 3 and maybe 4 sometime in the next few months.  I doubt
> the 2 drives will fail that soon, and even if they do, the data isn't
> that critical right away.

That there is probably the most important point. 

My sister is an Archiver; everything on the drive is important.

-- jra
Jay R. Ashworth                   Baylink                      jra at baylink.com
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates     http://baylink.pitas.com                     '87 e24
St Petersburg FL USA      http://photo.imageinc.us             +1 727 647 1274

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