Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 05 Jan 2001 16:25:56 +0200
From:      dxoch <dxoch@escape.gr>
To:        Daniel Lang <dl@leo.org>, freebsd-stable@FreeBSD.ORG
Subject:   Re: Vinum Question
Message-ID:  <3A55D971.42FB0B16@escape.gr>
References:  <20010105141224.E17176@atrbg11.informatik.tu-muenchen.de>

next in thread | previous in thread | raw e-mail | index | archive | help


Daniel Lang wrote:

> Hi Jim,
>
> [..]
> > Is there is any chance that vinum-related options in the loader.conf
> > (vinum_load ="YES")
> > can help me to boot from a vimum volume, or this is completely
> > irrelevant?
>
> I guess so. I know of 'vinum_load="YES"' only in /etc/rc.conf,
> not loader.conf or kernel.conf.
>

vi /boot/defaults/loader.conf  and you will find: vinum_load="NO"

>
> Although I guess you could immediately load the vinum.ko,
> before booting the kernel (i.e. load the kernel, load the
> module along with other modules like splash, then boot the kernel),
> but this does not help you to boot from a vinum device.
>
> The problem is, that in FreeBSD, the bootstrap loaders and the
> kernel reside in the root-partition.
> The booting process is described very good in
>
> http://www.freebsd.org/handbook/boot.html
>
> You will notice that each stage just knows as much about the
> the disks/filesystem as it needs.
> So boot1 knows about the disklabel and slices to find boot2
> boot2 knows about about UFS/FFS to find /boot/loader or
> /kernel. Themselves they reside in the MBR, or the boot-sector
> of the slice.
>
> Although loader is more sophisticated, it does not know about vinum,

I thought the same myself byt, in that case,
what is the purpose of the vinum_load option ?

>
> too. The first thing to know about vinum is the kernel with the vinum
> module loaded. In order to really boot from a vinum device,
> previous stages also have to know (at least something) about vinum
> devices. This is not the case, and I guess very difficult to
> implement. If you look at other OSes which allow booting from
> managed volumes, you may notice, that they have a special
> boot-filesystem (e.g. /stand, /boot), which must meet certain
> requirements, (like contigous block allocation, the first partition
> on disk/slice, etc). I guess it would be really painful to
> try to provide this functionality, with many drawbacks
> (I guess most in code-stability), huge effort required and
> little advantages.
> If you need average security agains disk-crashes, you can keep your
> data in vinum-volumes and back up the root-partition on a regular
> basis e.g. with dd. If you really need more security, go and
> buy a SCSI-SCSI raid-controller, which is seen as one or more
> single disks, independent of its real disks and configuration.
> You save yourself lots of trouble.
>
> Ok, this is just my opinion, based on some experience.

I dont dissagree at all, but this is not for me to deside.
Thank you very much Daniel.

>
>
> Best regards,
>  Daniel
> --
> IRCnet: Mr-Spock           - Burn them to ashes, then burn the ashes. -
> *Daniel Lang * dl@leo.org * +49 89 289 25735 * http://www.leo.org/~dl/*



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3A55D971.42FB0B16>