Re: [TCLUG:22757] Raid and other storage stories

[<Nick.T.Reinking@supervalu.com>]

Ahh, coolness.

In response to CPU Util, recently, IDE drives have had
lower CPU util than SCSI (because of DMA).  It's mostly
a driver issue, and the amount of CPU util is just a few
percent, anyways.

However, software RAID will seriously hurt your CPU Util.
The Escalade does the IDE RAID in hardware, so it only
uses a few percent of CPU to do your RAIDness.

Nick






jasonj@innominatus.com, on 10/17/2000 02:37:10 PM
To: tclug-list@mn-linux.org @ PMDF
cc:  
Subject: Re: [TCLUG:22757] Raid and other storage stories

No, RAID 10 is striped parity information. Similar to RAID 5 that has a 
dedicated
drive for parity informaiton. RAID 10 stripes the parity across all drives.  If 
one
drive fails, the replacement drive is rebuilt with the parity info from the 
other
drives. I think there is more performance than RAID 5.
0+1 is not 10. 0+1 is 2 drives striped, and 2 more mirroring the stripe.


Nick.T.Reinking@supervalu.com wrote:

> RAID 10 == RAID 0+1.
>
> The difference is that the Escalade does it in hardware,
> whereas the FastTrack and HighPoint do it in software.
>
> Nick
>
> jasonj@innominatus.com, on 10/17/2000 01:53:33 PM
> To: tclug-list@mn-linux.org @ PMDF
> cc:
> Subject: Re: [TCLUG:22757] Raid and other storage stories
>
> Escalada 6xxx does RAID 0, 1, and 10
>
> Fasttrak does 0, 1, and 0+1
> Highpoint does 0, 1, and 0+1
>
> Nick.T.Reinking@supervalu.com wrote:
>
> > Try www.elinux.com or www.thelinuxstore.com.
> >
> > Also, you don't need ATA/100 at all with just one device.
> >
> > As cool and fast as those 75GXPs are, they're not going to top
> > more than 40MB/sec.  Easily under 66MB/sec.
> >
> > AFAIK, you can do all the weird partitioning that you could do
> > with a real SCSI RAID controller.  The only bad thing about them
> > is that they don't support RAID 5.  Only RAID 0,1, and 0+1, and
> > JBOD, I think.
> >
> > Nick Reinking
> >
> > dopp@acm.cs.umn.edu, on 10/17/2000 01:14:41 PM
> > To: tclug-list@mn-linux.org @ PMDF
> > cc:
> > Subject: Re: [TCLUG:22757] Raid and other storage stories
> >
> > On Tue, Oct 17, 2000 at 12:54:46PM -0500, Nick.T.Reinking@supervalu.com 
wrote:
> > > The Escalade 6xxx series support ATA/66.
> >
> > Well, maybe they have an ATA/100 version planned...
> >
> > >
> > > They're really cool...
> >
> > They look cool...
> >
> > >
> > > 2-8 channels, 1 device/channel (which is why ATA/66 is
> > > plenty good).  It's completely internal.
> >
> > Internal is good.  I have a full tower, so I'll have the room.
> >
> > >
> > > The 3ware driver makes any RAIDed drives look like a single
> > > SCSI drive.
> > >
> > > Furthermore, the 3ware supports other cool things such as
> > > command queueing, etc.  Plus, they have an onboard co-processor.
> > > (same one most SCSI RAID cards have).
> >
> > How about logical partitioning?  Does the Escalade allow me to make, say, 4
> > drives into a single logical drive and then partition that logical drive
> > into say, 3 logical partitions which all appear as seperate drives to my
> > machine?
> >
> > The reason I ask is because I was thinking about the following setup:
> >
> > 4 30GB ATA/100 Deskstars
> > 1 logical drive
> > 2 logical partitions
> >
> > I suppose I could just take the 1 logical drive and partition it through
> > the OS, but if the controller handles it for me, it's that much nicer.
> >
> > >
> > > The FastTrack card is both poorly supported, plus it doesn't
> > > have a co-processor.  All it does for you is make your RAID
> > > drives look like one drive.  It's still all software otherwise.
> >
> > Ah, thanks for the heads-up.
> >
> > >
> > > >From what I've heard, these cards are pretty amazingly fast.
> > > IDE is faster than SCSI for one device, since the command
> > > set is much smaller (and faster).  Since there is only one device/channel
> > > on this controller... well, it's pretty amazing.  Plus, it has an
> > > Alan Cox approved open source driver in 2.2.15+.
> > >
> >
> > Eenteresteeng... I'll have to give it a try.  Where do you suggest I get
> > one of these controllers?  It looks like one can only buy them through
> > offical 3ware resellers.
> >
> > Gabe
> > --
> >
> 
--------------------------------------------------------------------------------
> > Gabe Turner                                    |           X-President,
> > UNIX Systems Administrator,                    | Assoc. for Computing
> Machinery
> > U of M Supercomputing Institute for            |    Univerisity of Minnesota
> > Digital Simulation and Advanced Computation    |       dopp@acm.cs.umn.edu
> >
> > "Dear Dr. Stupid: Why do I have to go to school?" -- Announcer
> > "Your parents are aliens!!  While you're at school, they shed their
> >  human skins and breathe dryer lint!!"
> >                                         - Dr. Stupid in "Ask Dr. Stupid"
> >
> 
--------------------------------------------------------------------------------
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tclug-list-unsubscribe@mn-linux.org
> > For additional commands, e-mail: tclug-list-help@mn-linux.org
> >
> >   ------------------------------------------------------------------------
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: tclug-list-unsubscribe@mn-linux.org
> > For additional commands, e-mail: tclug-list-help@mn-linux.org
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tclug-list-unsubscribe@mn-linux.org
> For additional commands, e-mail: tclug-list-help@mn-linux.org
>
>   ------------------------------------------------------------------------
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: tclug-list-unsubscribe@mn-linux.org
> For additional commands, e-mail: tclug-list-help@mn-linux.org


---------------------------------------------------------------------
To unsubscribe, e-mail: tclug-list-unsubscribe@mn-linux.org
For additional commands, e-mail: tclug-list-help@mn-linux.org