Re: Boot from software RAID. Sarge. Kernel 2.6.5. SATA.
On Sunday 02 May 2004 18:13, Kirill Lapshin wrote:
> Hello,
>
> I am trying to setup server with RAID 1. I got RAID working but I am
> having problems booting from it.
>
> Unfortunately box I am working on is quite dumb, only two drives can be
> connected to it and it can boot only from first drive.
>
> I installed minimal system on first drive, I can create RAID1 on
> non-root partitions, and it gets detected after reboot, can be mounted,
> etc.
>
> Now I want to set raid on root partition.
>
> I created partition on second drive of exact same size as root partition
> on first drive. Created a degraded RAID1 array out of it (with first
> drive missing). Copied contents of root partition on new array
> (/dev/md0). Changed fstab on new partition to mount /dev/md0 as root.
>
> First question: I copied root partition by logging into Knoppix and
> issuing 'dd if=/dev/hdc1 of=/dev/hdd1' command -- effectively bypassing
> RAID since Knoppix does not appear to have raid support. Is it ok? Or
> should I rather create an image from Knoppix and then dd it to /dev/md0
> from Debian?
>
I wouldn't do this. Instead, I recommend booting into the non-raid root,
mounting the raid partitions, then just using cp -p -r.
> Now I am trying to figure out how to boot from raid. Since I can't
> really boot from second drive, I decided to try booting from first drive
> using raid array as root partition.
>
I'm curious why you can't boot from the second drive. I believe lilo has
that capability...
> I added entry to my lilo config, named "LinuxRaid". It exactly the same
> as my regular "Linux" entry, with addition of "root=/dev/md0" parameter.
>
> System starts booting fine, but at the end I get kernel panic.
>
> Relevant log lines (note: i am retyping log by hand):
>
> md: raid1 personality registered as nr 3
> md: multipath personality registered as nr 7
> md: md driver 0.90.0 MAX_MD_DEVFS=256, MD_SB_DISKS=27
> device-mapper: 4.1.0-ioctl (2003-12-10) initialised: dm@uk.sistina.com
> [snip]
> md: Autodetecting RAID arrays.
> md: autorun ...
> md: ... autorun DONE.
> EXT3-fs: unable to read superblock
> EXT2-fs: unable to read superblock
> isofs_fill_super: bread failed, dev=md0, iso_blknum=16, block=32
> UDF-fs: No partition found (1)
> Kernel panic: VFS: Unable to mount root fs on md0
>
> When I boot from my regular root partition dmesg reports following:
>
> md: raid1 personality registered as nr 3
> md: multipath personality registered as nr 7
> md: md driver 0.90.0 MAX_MD_DEVS=256, MD_SB_DISKS=27
> device-mapper: 4.1.0-ioctl (2003-12-10) initialised: dm@uk.sistina.com
> [snip]
> md: Autodetecting RAID arrays.
> md: autorun ...
> md: ... autorun DONE.
> kjournald starting. Commit interval 5 seconds
> EXT3-fs: mounted filesystem with ordered data mode.
> VFS: Mounted root (ext3 filesystem) readonly.
> [snip]
> EXT3 FS on sda1, internal journal
> md: md0 stopped.
> md: bind<sdb1>
> raid1: raid set md0 active with 1 out of 2 mirrors
>
>
> So looks to me like RAID array gets activated after root partition is
> mounted. Any ideas how to handle this problem?
>
>
> --Kirill
It looks like your drivers are indeed loaded, but something is wrong with
your raid partition. I wonder if it's from the way you copied the files
over?
Sorry if this isn't much help.
Justin Guerin
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