[ubuntu] Migrating RAID 0 from Ubuntu 11.x to 12.x

Hey, guys.

I have a software RAID 0 configuration with two 2TB drives (4TB RAID 0). My Ubuntu 11.x installation appears to have been hacked (my /etc/mtab file is hosed and inaccessible), so I am putting together a new OS installation with Ubuntu 12.x with which I plan to just "hot swap" the existing drive, which means it has all the installed software, configurations, IPv4 address and hostname.

However, I'm a little nervous with the software RAID. I'm going to run the mdadm command:

to have the new OS automatically put the RAID drives back together ("fdisk -l" shows them as accessible in the 12.x OS). The data on the RAID is not irreplaceable, but it has literally taken me years to assemble its 3TB of data, and I'd rather not lose it.

My question is: If I run the above mdadm command within the new Ubuntu 12.x OS to test its ability to recover the RAID, and it overwrites the existing metadata, will that prevent me from using the RAID again with the original Ubuntu 11.x installation?

I'm assuming I could just run the mdadm assemble command again with the Ubuntu 11.x OS to revert the metadata, but I want to make sure that the actual data on the RAID is not going to be impacted by my testing actions during the incremental migration.

Thanks for your insights.