On Mon, 7 May 2007, Jeffrey B. Layton wrote:

Justin Piszcz wrote:

quoted

On Mon, 7 May 2007, Jeffrey B. Layton wrote:

quoted

Justin Piszcz wrote:

quoted

On Mon, 7 May 2007, Jeffrey B. Layton wrote:

quoted

Hello,

I apologize if this is a FAQ question or a typical newbie question,
but by google efforts have yielded anything yet.

I built a RAID-1 using mdadm (Centos 4.2 with 2.6.16.19 kernel
and mdadm 1.6.0-2). It's just two SATA drives that I created using:

mdadm --create --verbose /dev/md1 --level=raid1 --raid-devices=2 
/dev/sda1 /dev/sdb1

The md built correctly and I built an ext3 on it. I created 
/etc/mdadm.conf
and modified /etc/fstab to mount the device. But when I reboot, the 
kernel
drops into RAID repair mode because it can't seem to find /dev/md1 and
yells about not finding any valid superblock (I can get the exact 
message
if needed). However I can mount /dev/sda1 with no problems.

The only way I can get md1 back is to issue the command:

mdadm -A /dev/md1 /dev/sda1 /dev/sdb1

and everything works. I want to have /dev/md1 mounted automatically
on boot. I'm missing something simple here - how do I do this?

Sounds like a udev issue and/or you did not create the mdadm.conf 
properly. Show us your mdadm.conf.

ARRAY /dev/md1 level=raid1 num-devices=2 
UUID=e235ee6c:415f1494:23c28b59:afd20140
 devices=/dev/sda1,/dev/sdb1
ARRAY /dev/md0 level=raid1 num-devices=2 
UUID=7121b438:7d36f9f6:8aa9c8b3:b5b0d211
 devices=/dev/hdc1,/dev/hdd1

What distro?

CentOS 4.2. I've been reading something about raidautorun. Would help in this 
case?

Thanks!

Jeff

That is probably what you want-- also technically you don't 'need' to have 
the partitions set to 0xfd [Linux Raid Auto Detect], but that may help as 
well.

  fdisk -l /dev/sda

Disk /dev/sda: 74.3 GB, 74355769344 bytes
255 heads, 63 sectors/track, 9039 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

    Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1        2090    16787893+  fd  Linux raid autodetect
/dev/sda2   *        2091        2107      136552+  fd  Linux raid autodetect
/dev/sda3            2108        9039    55681290   fd  Linux raid autodetect


Justin.