nas
HowTo: Recover RAID volume and mount seperatly
My NAS storage was crashed, this time I was forced to move one of the raid volume to another server to make the service up because the volume contains all VM’s used by XEN server, most probably it is a LVM disk.
Everybody knows that we can’t simply attach the raid disk to another machine, so just follow the procedures below.
Once I attached the HDD to another machine. check the disk availability
root@ubuntu:~# mdadm --examine /dev/sdb
/dev/sdb:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : ec2c6fb2:f211cfa5:8dfa8777:4f08bfed
Name : openmediavault:storage
Creation Time : Fri May 9 16:22:45 2014
Raid Level : raid1
Raid Devices : 2
Avail Dev Size : 1953523120 (931.51 GiB 1000.20 GB)
Array Size : 976761424 (931.51 GiB 1000.20 GB)
Used Dev Size : 1953522848 (931.51 GiB 1000.20 GB)
Data Offset : 2048 sectors
Super Offset : 8 sectors
State : clean
Device UUID : 3a9e90a0:ca0e458e:c48e1b34:f3aaf06f
Update Time : Tue Jun 24 16:20:00 2014
Checksum : eaa54b02 - correct
Events : 24468
Device Role : Active device 1
Array State : .A ('A' == active, '.' == missing)
It sounds good now move to the next step, It should be create the block device md* so it will be reveal the partitions.
root@ubuntu:~# mdadm --assemble --force /dev/md127 /dev/sdb
You will get the output like this
root@ubuntu:~# ll /dev/md127 brw-rw---- 1 root disk 9, 127 Jun 24 14:27 /dev/md127
Now you can see the LVM names
root@ubuntu:~# lvs LV VG Attr LSize Origin Snap% Move Log Copy% Convert nfs storage -wi-ao 931.51g root@ubuntu:~# pvs PV VG Fmt Attr PSize PFree /dev/md127 storage lvm2 a- 931.51g 0 root@ubuntu:~# vgs VG #PV #LV #SN Attr VSize VFree storage 1 1 0 wz--n- 931.51g 0
Mount the partition manually
root@ubuntu:~# mount /dev/mapper/storage-nfs /export/
root@ubuntu:~# mount | grep nfs /dev/mapper/storage-nfs on /export type ext4 (rw)
That’s it now I got my files back,
Tech's you need !!!!! 