# Re: is it possible to change the UUID of an array?

- From: Neil Brown \<hidden\>
- Date: 2005-12-05 02:56:46 
- List: linux-raid
- Page: https://ratatoskr.run/linux-raid/2005/12/6595370
- Thread: https://ratatoskr.run/linux-raid/2005/12/6595370/t.md

```text
On Friday December 2, univac@comcast.net wrote:
> Hi,
> 
> I had a RAID-1 with two mirrors as my root partition.  I decided to
> fail/remove one of the mirrors prior to upgrading parts of the OS so
> that I'd have a backup just in case things went horribly wrong.  After
> doing the upgrade, I wanted to compare the two mirrors, so I assembled a
> new md with the failed mirror.  So far, so good.
> 
> The problem is that I now have two arrays with the same UUID.  I'm
> assuming that automatic assembly is now broken.  For now, I've changed
> mdadm.conf to specify the physical devices, but what I'd like to do is
> generate a new UUID for one of the mirrors.  I haven't found a way to do
> this without recreating the array.

Not easily, no.  Maybe I could add an
  --update=uuid:1234:5678.....
for mdadm-2.2 ....

NeilBrown
```