Any mdadm gurus here?

[dulcificum]

A few days ago my QNAP RAID-6 array randomly stopped responding even though the samba share seemed to be still responding. After about 5-10 minutes of this it randomly rebooted itself and asked me to run a checkdisk (e2fsck) when it loaded back up. I did this and it reported complete after about 1 hour and everything looked fine on the admin interface. However, the services had not restarted at all. So I rebooted through admin panel.

Now I can't access the NAS at all through admin panel or even ping it and the LCD display says "Config. Disks? >RAID 6". This means that the RAID is no longer recognised and in fact, all my system settings seems to be gone. When I SSH in, all the shares have disappeared :/

[/] # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
unused devices: <none>

I've run some commands to look at the array:

[/] # mdadm --examine --scan
ARRAY /dev/md9 level=raid1 num-devices=6 UUID=2cadcb78:68f1db30:09651c03:5ac6be59
ARRAY /dev/md6 level=raid1 num-devices=2 UUID=6300b0f8:b6e2c998:3628a2c8:465c1cc5
   spares=4
ARRAY /dev/md0 level=raid6 num-devices=6 UUID=22fd322d:10048ef5:8f36ad6a:b0ea696b
ARRAY /dev/md13 level=raid1 num-devices=6 UUID=04d49597:cfd44b87:f4ae2d46:f222307c

[/] # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
unused devices: <none>

Now someone is suggesting my best hope is to run

mdadm --assemble /dev/md0 --verbose

to try to reassemble the RAID-6.

Is this wise? Could it harm my chances of recovering the data? Is there anything else I should try first? My first priority is to not perform any destructive commands.

Any help or advice greatly appreciated!

[aidanjt]

Stop the other incorrect MD nodes first with

mdadm --stop /dev/md{9,6,0,13**

(the **'s should be a closing curly bracket, forum keeps swapping it out), and then assemble.

[dulcificum]

What exactly does that do? Explain it to me like I'm five. And those might be necessary for the NAS firmware, I think.

Is there any risk to running the assemble command? nd what might go wrong if I do/don't stop the other nodes first?

Thanks,