Comment 16 for bug 1066480

I can confirm this affected me.

I installed to a system with some disks pre-encrypted - an old /home which I was going to migrate to a new larger disk and some other data partitions. I also created some new encrypted data partitions on the large disk in preparation.

I assigned the encrypted partitions a mount point (/data, etc), expecting the installer to ask for the encryption password at some point

I specifically did not ask it to do any formatting.

On starting the install, the encrypted partitions were re-formatted and all the data lost.

Of course, I had a backup, but I ended up with a number of unecrypted partitions (other than home, which I chose to re-encrypt once I'd realised what had happened).

I can see that I made a mistake in assigning a filesystem type (ext4), expecting that the installer would want to know the underlying filesystem, but there should definitely be a warning before destroying data when the format flag is not set.