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

Brian Foddy bfoddy at visi.com
Tue Sep 25 04:06:30 UTC 2007


On Monday 24 September 2007, Jay R. Ashworth wrote:
> 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.

I never found the ES.1 series at $100 for 500GB.  But who's quibbling...

I'm happy so far.  Time will tell if I guessed right...
Brian


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