Date: Fri, 31 Mar 2000 11:16:13 +1000 From: Greg Lehey <grog@lemis.com> To: "Niels Chr. Bank-Pedersen" <ncbp@bank-pedersen.dk> Cc: freebsd-questions@FreeBSD.ORG, jesper@skriver.dk Subject: Re: Can one do a striped volume with mirrored plexes Message-ID: <20000331111613.A6178@mojave.worldwide.lemis.com> In-Reply-To: <20000330165535.C48576@bank-pedersen.dk>; from ncbp@bank-pedersen.dk on Thu, Mar 30, 2000 at 04:55:35PM %2B0200 References: <20000330165535.C48576@bank-pedersen.dk>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thursday, 30 March 2000 at 16:55:35 +0200, Niels Chr. Bank-Pedersen wrote:
> Hi,
>
> I have 3 Kingston DS-500 chassis' connected to 3 Tekram controllers,
> and I want to create one volume/filesystem that must be resilient to
> disk failure, chassis failure and controller failure.
>
> In vinum(8) it says that I can create a mirrored volume with two
> striped plexes, but that would only give me resilience against disk
> failure, so what I was thinking of was something like this:
>
> Chassis disks controller
>
> A 0 1 3 4 6 7 9 a x I
> B 0 2 3 5 6 8 9 b x II
> C 1 2 4 5 7 8 a b x III
>
> - where each number, 0-b (x being spare disks), represents a small
> mirror of 2 disks, and then all mirrors should be striped together
> to form one volume.
>
> With the above setup I believe I will have resilience
> against all "single-unit failures" - be it disk, chassis or
> controller, but I dont see any way to configure this with
> vinum.
Hmm. If I understand what you want here, this would do it:
drive 0A device /dev/chassisA/drive0
drive 1A device /dev/chassisA/drive1
drive 2A device /dev/chassisA/drive2
drive 3A device /dev/chassisA/drive3
drive 4A device /dev/chassisA/drive4
drive 5A device /dev/chassisA/drive5
drive 6A device /dev/chassisA/drive6
drive 7A device /dev/chassisA/drive7
drive 8A device /dev/chassisA/drive8
drive 0B device /dev/chassisB/drive0
drive 1B device /dev/chassisB/drive1
drive 2B device /dev/chassisB/drive2
drive 3B device /dev/chassisB/drive3
drive 4B device /dev/chassisB/drive4
drive 5B device /dev/chassisB/drive5
drive 6B device /dev/chassisB/drive6
drive 7B device /dev/chassisB/drive7
drive 8B device /dev/chassisB/drive8
drive 0C device /dev/chassisC/drive0
drive 1C device /dev/chassisC/drive1
drive 2C device /dev/chassisC/drive2
drive 3C device /dev/chassisC/drive3
drive 4C device /dev/chassisC/drive4
drive 5C device /dev/chassisC/drive5
drive 6C device /dev/chassisC/drive6
drive 7C device /dev/chassisC/drive7
drive 8C device /dev/chassisC/drive8
volume 0
plex org striped 512k
sd len 0b drive 0A
sd len 0b drive 0B
volume 1
plex org striped 512k
sd len 0b drive 0C
sd len 0b drive 1A
(etc).
> I guess I can run vinum on top of vinum, but I don't know how well
> that would perform, so has anyone tried something similar, or has
> suggestions as to how to achieve both the resilience from mirroring
> and the performance from striping with a setup like this?
That way madness lies.
Greg
--
When replying to this message, please copy the original recipients.
For more information, see http://www.lemis.com/questions.html
Finger grog@lemis.com for PGP public key
See complete headers for address and phone numbers
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000331111613.A6178>