Re: [PLUG] Ubuntu + RAID5

["Randy Schmidt" <x@altorg.com>]

Thanks for the info! I was seeing hints that I wasn't really getting
the benefits of hardware raid with the 1640 but didn't really
understand why. They even tell you on the website that if you want to
do RAID 5, to go with a different controller.

When I tried software raid before, I generated the mdadm.conf spitting
out the result of some command into the file (I can't remember exactly
what I did, but that's the gist). I think I was even able to restart
the raid using that file so that shouldn't be the problem, right?

I think I remember the boot process stopping at

LVM
or
Enterprise volume management system

and since I hadn't touched that stuff I didn't know why.

I think i'm going to give the software raid another shot...maybe I'll
test run failing drives and replacing them since that is one thing I
wasn't sure how it was handled.

Thanks again,
Randy

On 9/22/06, Will Dyson <will.dyson@gmail.com> wrote:
> On 9/22/06, Randy Schmidt <x@altorg.com> wrote:
> > I'm the highpoint 1640. The individual drives do show up when I first
> > boot without loading the module. I have gone back and forth on whether
> > I should do a software raid or a hardware raid. I went about setting
> > up a software raid first but ultimately settled on doing it the
> > hardware way. I like that the hardware will tell me when there is a
> > problem with one of the drives.
>
> I haven't been able to find explicit confirmation of this for your
> card, but most cheaper (< $300) "raid controllers" do not actually
> have any hardware support for raid. Instead, the driver provides its
> own implementation of software raid. So you are not gaining much over
> the Linux software raid (basicly, just bios support for booting from
> the array - and it is possible even that may be made to work in the
> future).
>
> Certainly, the 1640 does not appear to have any cache memory chips
> on-board, and so cannot accellerate the raid-5 XOR operations.
>
> Mdadm should be started on boot, and read /etc/mdadm.conf to
> automaticly start the arrays specified there. If this is not happening
> (and you have /etc/mdadm.conf correctly setup), the problem may be
> that you need to re-generate the initrd for your kernel. The following
> command should do the job for you:
>
> sudo dpkg-reconfigure linux-image-2.6.15-27-686 (or whatever kernel
> you have installed)
>
> Also, it just occured to me that the performance problem you are
> seeing with the highpoint driver may be caused by a conflict between
> the normal linux driver for the individual drives and the highpoint
> array driver.
>
> --
> Will Dyson
> ___________________________________________________________________________
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--
Randy Schmidt
x@altorg.com
267.334.6833
___________________________________________________________________________
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug