I've been following this thread as I research using software RAID1 on a
production system
I haven't read the new HOWTO yet (i plan to sometime today if i get time)
but I dont think i understand the concept of bootable, root RAID1 so far.
What I got so far is you have a small bootable partition which is
not-raided, and then every other partition on that drive raided to like
partitions on the mirror drive.
The thing I TOTALLY don't get is if the first drive dies, how can
you boot the 2nd drive (mirror) when you're still losing the small
bootable partition (as it's still part of drive 1). Of course you can put
this bootable partition on a seperate drive, but you still dont have the
redundancy because THAT drive can die.
Wouldn't it be easier to stick the kernel, lilo config, relevant boot info
on a floppy and boot raid1 systems from that?
perhaps i'm missing something..more likely that not :-)
-Tony
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Anthony J. Biacco Network Administrator/Engineer
[EMAIL PROTECTED] Intergrafix Internet Services
"Dream as if you'll live forever, live as if you'll die today"
http://cygnus.ncohafmuta.com http://www.intergrafix.net
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On Wed, 27 Oct 1999, Bruno Prior wrote:
> There seems to be quite a lot of confusion about root-RAID out there.
>
> > > to /mnt/newroot/boot. Then after running "lilo -r /mnt/newroot" I get
> > > the following error:
> > > "Sorry, don't know how to handle device 0x0900"
> > >
> > > What does the above mean and how to i fix it?
> >
> > It does mean that lilo doesn't know anything about md device. Change the
> > line containing "root=" in lilo conf to "root=0x900". This way lilo tells
> > the kernel properly where from mount the root fs.
>
> This shouldn't be necessary. The root= line in /etc/lilo.conf is simply a
> pointer to a filesystem that is passed to the init scripts. It doesn't require
> reading of that filesystem, so lilo shouldn't have a problem with it pointing to
> a RAID array. I have root=/dev/md? in my machines with no problems.
>
> If lilo is reporting "Sorry, don't know how to handle device 0x0900", that means
> it is being asked to read from or write to /dev/md0. The lines in your lilo.conf
> that might require this include the "boot=", "install=", "map=", "loader=" and
> "image=" lines. If any of these lines points to something on /dev/md0, or if any
> of them is missing and the default (mostly in /boot) is on /dev/md0, and lilo
> cannot handle /dev/md0, then you will get this message. You can get round it by:
>
> (a) Getting the latest patched lilo from RedHat or applying the lilo.raid1 patch
> and rebuilding it yourself (if /dev/md0 is RAID-1)
> (b) Providing lilo with the geometry of one of the devices in the array (again
> if /dev/md0 is RAID-1)
> (c) Using a slightly-adapted grub instead of lilo (again if /dev/md0 is RAID-1)
> (d) Making sure the files to which these lines point are not on a software-RAID
> array.
>
> Check the mailing list archives for instructions on these methods.
>
> > Yes. Put everything needed to run lilo to a non-raided partition.
>
> Almost. But not exactly. Put everything needed to *boot from* lilo on a
> non-raided partition. lilo.conf doesn't have to be on a non-raided partition
> itself. It isn't read during the boot process. It is read when installing lilo.
> At this time, your system is fully operational, so lilo can easily read it from
> a RAID array. The best advice would be to leave it in /etc, where it should be
> by default. Nor do you need /dev or any of its devices on a non-RAIDed
> partition. In fact, all you need on a non-RAIDed partition is the kernel image,
> the system map, boot.b and associated files. In other words, the files that live
> in /boot by default. So the simplest strategy is to stick with the default
> filesystem structure, and have /boot on its own tiny partition. Then you can use
> a bog standard /etc/lilo.conf, and run lilo straight without the need to pass it
> parameters.
>
> Cheers,
>
>
> Bruno Prior [EMAIL PROTECTED]
>
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Egon Eckert
> > Sent: 26 October 1999 18:18
> > To: Marcos Lopez
> > Cc: [EMAIL PROTECTED]
> > Subject: Re: Root RAID and unmounting /boot
> >
> >
> > > to /mnt/newroot/boot. Then after running "lilo -r /mnt/newroot" I get
> > > the following error:
> > > "Sorry, don't know how to handle device 0x0900"
> > >
> > > What does the above mean and how to i fix it?
> >
> > It does mean that lilo doesn't know anything about md device. Change the
> > line containing "root=" in lilo conf to "root=0x900". This way lilo tells
> > the kernel properly where from mount the root fs.
> >
> > > it get hammered. I think i am close just have to figure out this lilo
> > > thing.
> >
> > Yes. Put everything needed to run lilo to a non-raided partition.
> >
> > For example, this is my 'ls -lR /mnt/hda7' :
> >
> > boot:
> > total 23
> > -rw-r--r-- 1 root root 512 Jul 28 16:09 boot.0300
> > -rw-r--r-- 1 root root 4540 Feb 2 1999 boot.b
> > -rw-r--r-- 1 root root 612 Feb 2 1999 chain.b
> > -rw------- 1 root root 14336 Jul 28 16:09 map
> > -rw-r--r-- 1 root root 620 Feb 2 1999 os2_d.b
> >
> > dev:
> > total 0
> > brw-rw---- 1 root disk 3, 0 Jul 21 1998 hda
> > brw-rw---- 1 root disk 3, 7 Jul 21 1998 hda7
> >
> > lilo:
> > total 933
> > -rw-r--r-- 1 root root 176 Jul 28 14:43 lilo.conf
> > -rw-r--r-- 1 root root 451591 Jul 28 15:49 zImage
> > -rw-r--r-- 1 root root 494994 Feb 4 1999 zImage-bak
> >
> > Then run lilo like this:
> >
> > archiv:/home/egon# lilo -r /mnt/hda7 -C /lilo/lilo.conf
> > Added Linux-smp *
> > Added Linux-bak
> > archiv:/home/egon#
> >
> > Here's my lilo.conf:
> >
> > boot=/dev/hda
> > root=0x900
> > install=/boot/boot.b
> > map=/boot/mapvga=ext
> > delay=30
> > image=/lilo/zImage
> > label=Linux-smp
> > image=/lilo/zImage-bak
> > label=Linux-bak
> > read-only
> >
> >
> > Simple.
> >
> > Egon
> >
> >
>
