Re: Moving mdadm raid volume to new OS install

[Pascal Hambourg <pascal@plouf.fr.eu.org>]

Sam Martin a écrit :
> 
> You mean test whether i can bring the raid vol up by booting into 64bit debian from usb?

Yes.

> i did a mdadm -e on one of the disks in the array
> 
> root@HTPC-NAS:~# mdadm -E /dev/sdc1
> /dev/sdc1:
>           Magic : a92b4efc
>         Version : 1.2
>     Feature Map : 0x0
>      Array UUID : 25a729b1:71f5193b:6abe8ba9:21e698f5
>            Name : HTPC-NAS:0  (local to host HTPC-NAS)
>   Creation Time : Thu Dec 20 12:25:56 2012
>      Raid Level : raid1
>    Raid Devices : 2
> 
>  Avail Dev Size : 5860268032 (2794.39 GiB 3000.46 GB)
>      Array Size : 2930133824 (2794.39 GiB 3000.46 GB)
>   Used Dev Size : 5860267648 (2794.39 GiB 3000.46 GB)
>     Data Offset : 262144 sectors
>    Super Offset : 8 sectors
>           State : clean
>     Device UUID : fe1998ea:8535a654:31083985:d8c560c1
> 
>     Update Time : Thu Feb  7 09:01:38 2013
>        Checksum : ad4320a8 - correct
>          Events : 51
> 
> 
>    Device Role : Active device 1
>    Array State : AA ('A' == active, '.' == missing)
> 
> 
> I think the 1.2 means it's a no go in terms of running the disk independently of the raid vol.

Correct.
Actually, it should be possible to mount the filesystem on the RAID1
partition using a loop with the data offset indicated above (262144
sectors of 512 bytes), but that's getting a bit dodgy.

# mount -o ro,loop,offset=$[262144*512] /dev/sdc1 /mount/point