Move Ceph jounral to SSD?

Hi all,

I was thinking about adding a (server class) SSD each to my three ceph nodes.
Currently, each node has two OSDs and the journal for each is on the drive itself.
Now, I have a few questions about concepts:

- Can the two journals reside on the same partition on the SSD?
- Or do I have to provide one partition per OSD?
- Is there a way to migrate the journal or do I have to re-create the OSD?
- Are there any other ceph-related options / configuration items that would need to be changed to accommodate the new setup?

Finally, I was leaning towards an Intel S3700 Series SSD for durability. Anyone has experience with those or other recommendations?
How about size? Can I make do with the 100G model or is more space necessary?

Thanks,

Martin