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>
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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
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