AIX + disk redundency input needed

OK guys & gals this is the issue: i am trying to sort out all the disks in all of our AIX servers.

12 hdisks w/ mirroring (so only 6 disks in uses @ any time)

2 volume groups (rootvg, vg1)

this does include muliple informix databases and misc. data.

Do you think it would be wise to break the mirror and go with a striping w/ parity? or should i stick w/ the mirroring as it is right now?

Backups (level 0) are done on all Logical Volumes (filesystems) nightly. Data loss is not permitted. Can i have some of your guys input as to what you think would be best.

I want to lean toward striping w/ parity so if a disk fails i can swap it out on the fly and lose no data. and gain some disk space.

Using straight mirrors (RAID 1) or using
striping w/parity (RAID 5 i assume) is really
a tradoff of sorts. Yes you will get better
use of your disks using RAID 5 however recovery
from a disk failure takes longer and in general,
write performance will be degraded during
normal operation. RAID 1 gives you the best
failure recovery and redundancy but at a much
higher cost. Also, RAID 1 does not affect write
performance very much at all. If you've got
the bucks, and as you say, data loss is not
permitted, I'd stick with RAID 1.