Re: [Nolug] NAS

The one "bad" thing about high-capacity drives is, well, their high
capacity.

Back In The Day, you'd create a 1TB RAID-10 set out of 14 SCSI-320
146GB drives and 4 or 5 SCSI cards. The parallelism made for very
high IO rates, but at the cost of a shelf or two, 2 or 4 PSUs, a
handful of BBC SCSI cards, cables, etc, etc, ad nauseum. Serious
coin! More if your existing racks are already full and you thus
need to also buy a new rack, fans, shelves, blah blah. REALLY
Serious Coin, especially if the corporation mandates Tier 1 vendors.

Even now, for "Enterprise" production (as opposed to archival) work,
I'd spec 320GB or 146GB 6Gbps 15K SAS drives, depending on how much
speed is needed.

On 2010-04-10 14:45, John Souvestre wrote:
> Hi Ron.
>
> Right. I believe that Raid 10 beats Raid 5 in all of the specs. I certainly
> prefer it.
>
> The only possible down side is that you need an even number of drives. So where
> a 3 drive Raid 5 might be large enough, you would need a 4th drive to go with
> Raid 10.
>
> I also echo the comments about not trusting software Raid. I had the FreeBSD
> version fail on two different boxes in the past. On the other hand, I've had
> drive in my Cobalt RaQ fail twice and the OS handled the situation like a dream.
>
> John
>
> John Souvestre - New Orleans LA
>
> > -----Original Message-----
> > From: owner-nolug@stoney.kellynet.org [mailto:owner-
> > nolug@stoney.kellynet.org] On Behalf Of Ron Johnson
> > Sent: Saturday, April 10, 2010 2:39 PM
> > To: nolug@nolug.org
> > Subject: Re: [Nolug] NAS
> >
> >
> > RAID5 best of both worlds?? That *highly* debatable, since it's
> > write performance stinks. You need scads of BBC to make it effective.
> >
> > On 2010-04-10 14:14, Chris Jones wrote:
> > > Well, there's no such thing as raid10 with 2 drives. You need at least
> > > 4 drives for raid10. With 2 drives it would be raid1. Or raid0, but
> > > only a fool would put important data on a raid0. ;) raid0 is best for
> > > use as a temporary place for data processing. Raid5 is the best of both
> > > worlds, and is the most cost effective.
> > >
> > >> On Apr 10, 2010 1:41 PM, "Joey Kelly" <joey@joeykelly.net
> > >> <mailto:joey@joeykelly.net>> wrote:
> > >>
> > >> On Sat April 10 2010 1:29 pm, Petri Laihonen wrote:
> > >>
> > >> > On Sat, Apr 10, 2010 at 1:13 PM, Joey Kelly <joey@joeykelly.net
> > >> <mailto:joey@joeykelly.net>> wrote:
> > >> > > On Sat April 10 2010 1...
> > >>
> > >> OK, let me be less cryptic.
> > >>
> > >> RAID5 with 3 drives, or RAID10 with two... fine, lose one drive,
> > >> you're still
> > >> OK. Forget I even said anything.
> > >>
> > >> BUT... I do have to step in and complain loudly about software RAID.
> > >> If you
> > >> don't care about your data, feel free to set up software RAID.
> > >>
> > >> The same thing goes for Fake RAID. If you like your data and want to
> > >> keep it,
> > >> get a real controller.
> >

-- 
Dissent is patriotic, remember?
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