Hi,
I'm in the process of trying mdadm for the first time
I've been trying stuff out of tutorials, etc.
At this point I know how to create stripes, and mirrors.
My stripe is automatically restarting on reboot, but the degraded mirror isn't.
drew einhorn wrote:
Hi,
I'm in the process of trying mdadm for the first time
I've been trying stuff out of tutorials, etc.
At this point I know how to create stripes, and mirrors.
My stripe is automatically restarting on reboot, but the degraded mirror isn't.
Is the partition type set to FD?
On Mon, Jun 16, 2008 at 12:09 AM, Les Mikesell lesmikesell@gmail.com wrote:
drew einhorn wrote:
Hi,
I'm in the process of trying mdadm for the first time
I've been trying stuff out of tutorials, etc.
At this point I know how to create stripes, and mirrors.
My stripe is automatically restarting on reboot, but the degraded mirror isn't.
Is the partition type set to FD?
That's the problem, but now I'm having trouble fixing it.
md1 has a single partitions md1p1
[drew@funGus ~]$ sudo fdisk /dev/md1
The number of cylinders for this disk is set to 244123680. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK)
Command (m for help): p
Disk /dev/md1: 999.9 GB, 999930593280 bytes 2 heads, 4 sectors/track, 244123680 cylinders Units = cylinders of 8 * 512 = 4096 bytes
Device Boot Start End Blocks Id System /dev/md1p1 1 244123680 976494718 fd Linux raid autodetect
Command (m for help): q
but the attempt to create md2 fails:
[drew@funGus ~]$ sudo mdadm -C -ayes /dev/md2 --level=raid1 --raid-devices=2 missing /dev/md1p1 mdadm: Cannot open /dev/md1p1: No such file or directory mdadm: create aborted
[drew@funGus ~]$ sudo mdadm -C -ayes /dev/md2 --level=raid1 --raid-devices=2 missing /dev/md1p1 mdadm: Cannot open /dev/md1p1: No such file or directory mdadm: create aborted
Hmm. That's right. I does not exist.
[drew@funGus dev]$ ls -l /dev/md* brw-r----- 1 root disk 9, 0 Jun 16 06:43 /dev/md0 brw-r----- 1 root disk 9, 1 Jun 16 06:46 /dev/md1 brw-r----- 1 root disk 9, 2 Jun 16 06:48 /dev/md2 [drew@funGus dev]$
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On Mon, Jun 16, 2008 at 07:02:17AM -0600, drew einhorn wrote:
On Mon, Jun 16, 2008 at 12:09 AM, Les Mikesell lesmikesell@gmail.com
Is the partition type set to FD?
That's the problem, but now I'm having trouble fixing it.
md1 has a single partitions md1p1
[drew@funGus ~]$ sudo fdisk /dev/md1
No; you need to set the partition type of the underlying physical partitions on /dev/sda or wheverever your data really lives. This is what is picked up
eg on my machine I have 4 disks in a RAID5 thus: md3 : active raid5 sdd4[3] sdc3[2] sdb2[1] sda1[0] 1465151808 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
So the raw partitions are sda1 sdb2 sdc3 sdd4
If I look at sda:
# fdisk -l /dev/sda
Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System /dev/sda1 * 1 60801 488384001 fd Linux raid autodetect
That's where the "fd" needs to be.
drew einhorn wrote:
Hi,
I'm in the process of trying mdadm for the first time
I've been trying stuff out of tutorials, etc.
At this point I know how to create stripes, and mirrors.
My stripe is automatically restarting on reboot, but the degraded mirror isn't.
Did you create /etc/mdadm.conf ?
echo "DEVICE /dev/sd*" > /etc/mdadm.conf mdadm --brief --examine /dev/sd* >> /etc/mdadm.conf
Check the raid with cat /proc/mdstat
It tells you which devices are part of the array.
Finally put the raid flag on the partitions. I'm not sure whether it's really needed, I just do it: parted /dev/sda set 1 raid set 2 raid print 1 0.031 101.975 primary ext3 boot, raid 2 101.975 194474.355 primary raid quit
Theo
-
drew einhorn -
Les Mikesell -
Stephen Harris -
Theo Band [GreenPeak]