Re: Install and RAID
Jason Gunthorpe wrote:
>
> On Sat, 27 Jan 2001, Glenn McGrath wrote:
>
> > Nathan E Norman wrote:
>
> > > Yeah right, I'm going to build a high performance server on IDE
> > > <snicker>
>
> > It is an undisputable fact that IDE gives better performance per $ than
> > SCSI. You realise the speed of a drive is primarily dependent on its
> > RPM's not its interface (or its pricetag).
>
> Do you realize that the current fastest disks are available only in
> SCSI/Fibre channel varients? Show me a 15K RPM IDE..
>
A 7200RPM scsi drive isnt necessarily faster than a 7200 RPM IDE drive
and is probably costs 75% more.
> You realize that the speed of a RAID array is primariy dependent on the
> number of spindals and the aggregate bandwidth available from each disk?
> Show me your fastest IDE based RAID and I'll show you a 64 drive Fibre
> Channel system that eats it for lunch :>
>
> Nathan did say high performance, not cheap.
>
Why not distribute the load to a number of smaller servers all using
commodity hardware and network them well.
Unless the application is something that you cannot use the divide and
conquer rule on then using a high performance machine such as you
mention is unwarrented.
You could probably buy over a dozen "normal" servers for the price of
one of your "high performance" servers, and the collective performance
of the small servers will be more than the one high performance machine.
The only problem is getting multiple servers to efficiently work as one,
which depends on the application.
> > Ever seen a hardware raid card with as much power as a cpu ?
> > If you worried about overloading you system get a MP mobo.
>
> Yes actually :> My new employeer: http://www.yottayotta.com
>
> These cards have more MIPs, RAM and bandwidth than small servers..
> especially when they are clustered ...
>
Fair enough, do they cost more than a commondity cpu and some extra ram
?
> Software RAID is a bit of a win on small scale, unmanaged RAID systems
> that need to be low cost. Dedicated RAID controllers dominate everything
> else.
>
> Here is a big hint for you, Linux doesn't even have an enclosure
> management driver to go along with the software RAID stuff, making it
> impossible to use Linux in conjunction with a JBOD enclosure and be able
> to hot swap drives.
>
Yea, as i see it hot swapping is the main advantage to the type of setup
your describing, its a lot of money pay for this one benefit.
Glenn
Reply to: