software raid 5 after reinstallation

[yanaek]

I found similar topic, but it's not the same case: http://ubuntu-virginia.ubuntuforums.org/showthread.php?t=1410563, so..

I have:

operating system installed on SSD drive (Kubuntu 10.10 amd64 on OCZ Vertex 64GB).
software raid made of 6 normal hard disks (1TB each)


I want to reinstall Ubuntu on SSD without loosing data from my software raid.

What will happen when i do this? Will new Ubuntu recognise all partitions that were made on hard disks? Or maybe i have to back up /etc/mdadm/mdadm.conf from my current installation and then, on new Ubuntu install mdadm and copy mdadm.conf there?

I have a lot of data on this software raid 5


$ sudo vgdisplay
--- Volume group ---
VG Name Storage
System ID
Format lvm2
...
VG Size 4.55 TiB

it would be nice to not loose it without backup.

mdadm.conf


DEVICE partitions

# auto-create devices with Debian standard permissions
CREATE owner=root group=disk mode=0660 auto=yes

# automatically tag new arrays as belonging to the local system
HOMEHOST <system>

# instruct the monitoring daemon where to send mail alerts
MAILADDR root

# definitions of existing MD arrays
ARRAY /dev/md0 level=raid5 num-devices=6 UUID=973ba49b:89a35e81:9615a9b1:92f14bda


So. any risks? I'd like to do the reinstallation because one year ago i installed Ubuntu 9.10 on this SSD and its partitions are not aligned well. Also i upgraded it from 9.10, through 10.04 to 10.10 and could be messy. I want clean new install of 10.10

[SaturnusDJ]

This should work.
How about trying it out by booting from Live CD and then mounting the RAID setup and LVM?

[yanaek]

perfect!, thanks for the hint

it works flawlessly

from live usb:

fdisk -l # to check which disks are raid

$ sudo mdadm --assemble /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdg1 /dev/sdh1

then it is possible to mount all raid/lvm partitions, great!