Arch Linux

wantilles

Member

From: Athens - Greece

Registered: 2007-03-29

Posts: 327

Unable to move existing installation to software RAID-1 setup

I have an existing Arch Linux amd64 installation which I want to move to a RAID-1 setup.

I followed the following Wiki article:

Arch Linux Wiki - Installing with Software RAID or LVM

with necesary changes applied and some supplemental advice from the equivalent Gentoo Wiki article:

Gentoo Linux Wiki - HOWTO Install on Software RAID

mainly for the "--assume-clean" command-line switch to mdadm.

With a Larch live CD I took a tarball backup of each partition.

Then with cfdisk partitioned the disks.

And copied their partition tables to their RAID-1 mirrors:

sfdisk -d /dev/sda | sfdisk /dev/sdb

Now, I cannot boot Arch on the RAID-1 setup.

After initramfs is finished, I get a kernel panic as the "/" partition cannot be mounted.

The mkinitcpio.conf that created my kernel is this:

MODULES="ahci pata_amd ata_generic sata_nv sata_sil"

HOOKS="base udev autodetect pata scsi sata usbinput keymap raid lvm2 filesystems"

My rc.conf is this:

MODULES=(raid1 powernow-k8 fuse forcedeth ac battery button fan thermal loop)

My fstab ("/" and "/boot" lines) is this:

/dev/md0 /boot ext3 noatime 0 1
/dev/md1 / ext3 noatime 0 1

And my menu.lst is this:

timeout   5
default   0
color light-blue/black light-cyan/blue

title  Arch Linux
root   (hd0,0)
kernel /vmlinuz26 root=/dev/md1 ro swncq=1 md=0,/dev/sda1,/dev/sdb1 md=1,/dev/sda2,/dev/sdb2
initrd /kernel26.img

I even tried another shot by passing all ten RAID-1 arrays (md0 to md9) as kernel parameters, but still, no effect.

Any help would be greatly appreciated.

PS: I have created a correct mdadm.conf file with:

mdadm -D --scan >>/etc/mdadm.conf

Last edited by wantilles (2008-09-08 08:28:20)

lilsirecho

Veteran

Registered: 2003-10-24

Posts: 5,000

Re: Unable to move existing installation to software RAID-1 setup

My experience with raid suggests that mdadm setups work after boot-up as "software raid".  The array is assembled and "ID'd" with mdadm --assemble command.

IMHO In order to utilize mdadm for boot-up, how does the user "assemble" before the elements needed for mdadm --assemble are accessible?

IMHO My understanding of booting with raid involves the use of dmraid, a "software" raid program which can be adapted to boot use.  It involves changes to the boot sequence to prevent loss of dmraid params during the boot processes such as hardware detect AFAIK.

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DREMA

Member

From: México

Registered: 2009-03-09

Posts: 15

Re: Unable to move existing installation to software RAID-1 setup

Hi!
Do you solve this?

I'm looking for moving my existing partition to software raid too, but mine is from one drive t2 a pair of drives in raid 0.

Any step I need to be very careful?

Thanks

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