[CentOS] fixing partition alignment ?

Hi there,

I've discovered that most of the hard drives used in our cluster got
misaligned partitions, thus crippling perfs. Is there any way to fix
that without having to delete/recreate properly aligned partitions, then
format it and refill disks ?
I'd be glad not to have to toy with moving several 10s of TB disk by
disk :D (most disks are JBOD as we're using a fault tolerant network
FS, moosefs not to name it).
<insert your favorite search engine> wasn't helpful, unfortunately.
Drives are ext4, driven by C6 x86_64.

Thanks,
Laurent.