[linux-lvm] mirroring boot and root

[linux-lvm] mirroring boot and root

[Vissers, Ron]

Hi,
Can someone point me in the right direction.
I'm coming from hpux-land.  They allow for mirroring of the boot lvm's.

Is this doable under linux/lvm?

Thanks,
Ron

     _/_/   _/_/_/_/_/ _/_/_/   Ron Vissers
  _/    _/     _/       _/      IT Systems & Operations Team Lead
 _/  _/_/     _/       _/       Quad/Tech International 
_/    _/     _/       _/        ph:414-566-7643  fx:262-246-1545
 _/_/  _/   _/     _/_/_/       Ron.Vissers@qtiworld.com

Re: [linux-lvm] mirroring boot and root

[evan.day]

> Hi,
> Can someone point me in the right direction.
> I'm coming from hpux-land.  They allow for mirroring of the boot
lvm's.
> 
> Is this doable under linux/lvm?

Linux LVM does not have any support for mirroring in itself.  However,
the linux kernel does contain software RAID support - it is possible to
run LVM on top of a RAID 1.  I do this, and have successfully booted 
from each disk with the other disk in the RAID down.

LILO 21.7 contains support for placing a boot sector on RAID devices.  I
used install-mbr to put a boot MBR on sda and sdb, then lilo to put a 
LILO boot sector on /dev/md0, which is sda1 and sdb1.  The rest of my
system is built on PV /dev/md1, which is sda4 and sdb4.

I'm not sure if there are future plans to add mirroring to LVM or not. 
However, by building LVM on top of RAID, you don't have to worry about
quorum when you lose a disk.  The first time we lost a boot drive on 
HP-UX at work it was quite a learning experience :)

--
Evan Day <evan.day@home.com>
GPG:1024D/237C1C84 FP:1615 E312 A6D1 542B C4A6 38B5 69B1 2844 237C 1C84
"My bologna has first name, it's H-O-M-E-R..."

Re: [linux-lvm] mirroring boot and root

[Russell Coker]

On Saturday 02 June 2001 17:21, evan.day@home.com wrote:
> LILO 21.7 contains support for placing a boot sector on RAID devices.  I
> used install-mbr to put a boot MBR on sda and sdb, then lilo to put a
> LILO boot sector on /dev/md0, which is sda1 and sdb1.  The rest of my
> system is built on PV /dev/md1, which is sda4 and sdb4.

I tried the booting from RAID-1 thing on one of my IDE systems.  It seems 
impossible with the current LILO because it writes different boot data to 
each drive, so if the first drive is removed the other drive becomes BIOS 
device 0x80 and won't boot because LILO expects 0x81.

The next version of LILO may address this...

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