At the moment pmspare is created as a linear volume. There is no way how to make it redundant. lvcreate and lvrename fails with: Names including "_pmspare" are reserved. Please choose a different LV name. I assume we may eventally support 'lvconvert -m+X' for _pmspare. On the other hand _pmspare is 'last resource' weapon not even normally used - it's reserved space for recovery operation when everything else fails thus it should not really matter which type is that. What user should be always able to make is to 'pvmove & lvconvert' real _tmeta & _cmeta volumes. _pmspare does not normally hold any data so it's rather lost space to use raid for such volume - lvm2 never automatically 'deletes' old metadata volume, so there should be always original version on raid.