I installed debian on /dev/sda. /dev/sda1 is /boot /dev/sda2 is '/' dev/sda3 is swap,
then I made a degraded raid1 with /dev/sdb


When booting from /dev/sda I have:

server:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6]
[raid10]
md0 : active raid1 sdb1[1]
104320 blocks [2/1] [_U]

md1 : active raid1 sdb2[1]
243585472 blocks [2/1] [_U]

md2 : active raid1 sdb3[1]
505920 blocks [2/1] [_U]


Data was copied over so when booting from /dev/sdb md0 will be /boot, md1 will be '/' and md2 will be swap. But see what I got (booting from /dev/sdb):

server:/# cat /proc/mdstat
Personalities : [raid1]
md1 : active raid1 sdb2[1]
243585472 blocks [2/1] [_U]

unused devices: <none>


As you can see md0 and md2 is missing why?
How has this happen?





Here some extra information:

# fdisk -l /dev/sdb

Disk /dev/sdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 1 13 104422 fd Linux raid autodetect
/dev/sdb2 14 30338 243585562+ fd Linux raid autodetect
/dev/sdb3 30339 30401 506047+ fd Linux raid autodetect

Did you clear the superblocks on both drives, and did you convert all partitions on the second drive to 0xfd?

Double check if your sequence was identical to the one described here:
http://www200.pair.com/mecham/raid/r...aded-etch.html. If not, go back to a point in the instruction list where you know you had a condiguration which worked as expected. Then redo your actions.

I can assure you it works in Debian, followed this list last week also on a sda/sdb configuration.

jlinkels

Thanks . It gave me a hint and the problem was caused by a wrong configuration of mdadm.

In "/etc/default/mdadm" there must be a AUTOSTART=yes